DSBRatUse

FAQs about Deep Sand Beds, Rationale/Use

Largely for more-reef type systems, for nutrient export, enhanced denitrification, biomineral and alkalinity sourcing, habitat for beneficial infauna...

New 1000 gallon set up: substrate question and how to move 3 year ... subst. sel., DSBs 1/2/12
old fish to it
Hello to all and Happy New Year! I work out of my house and I am on your website everyday. My knowledge has now exceeded the LFS I am afraid and I am tired of making the wrong decisions based off their bad advice. I have no "fish buddies" -- just you guys -- and I consider you my "fish buddies" and take your advice. My addiction to the hobby has grown in the past three years since I started out with a 120 in my upstairs office.
I have built out my basement recently ( will refer to it later in the email as "downstairs") around some showcase tanks that are built into a wall with catwalk access behind the wall.
Before I pull the trigger on buying 2400 lbs of sand for the substrate for these new tanks -- just want to double check with Bob Fenner or the crew ( it is my dream to some day meet Bob)
<Come out to MACNA in TX this year>
on this large sand purchase -- as it will be expensive and the LFS does not recommend buying this much sand ( first time they are saying buy less not more).
<Not necessary... if you have other means of providing biomineral and alkalinity... and your livestock doesn't require such>
The new set up downstairs is (1) 265 gallon tank and (3) 150 gallon tanks going back to a remote 300 gallon sump. I have the water and salt in the tanks and it is all plumbed and running. The question is how much sand to use as substrate to do it right to help with nitrate reduction and not create a bad situation from use of sand at less than 4" as I read on WWM.
<Mmm, yes... though a DSB could be just part of all the tied in volume
here>
LFS recommends like 80 lbs sand for (1) 150 tank for example. I think this would be less than 1" of sand.
<Yes>
I have other tanks upstairs right now in operation for 3 years that will eventually be torn down and the inhabitants and live rock brought downstairs. I measured the sand off at like 2" in those tanks that the LFS set up. I have always had high nitrate in these tanks. The LFS wants me to mimic the sand depth like I have upstairs for the new downstairs tanks -- so basically like 1 to 2" deep ( aesthetic) downstairs.
<So?>
I am afraid that this aesthetic depth -- which I do like the looks of -- will cause problems with toxic water situations from what I read?
<Yes; your high nitrate situation/s will continue>
So I am trying to figure out if I am over thinking this -- or if I have to have 4" to be safe of sand depth -- or if 1" - 2" would be OK to use....I am not real excited about the depth of 4" of sand. I don't like the aesthetics of it or the cost -- but want to use sand for sure as a substrate and want to use more than 1/2" of sand in the tanks
<Mmm, place this depth, or greater, in even just part of your 300 gal. sump>
From what I gather -- to do a DSB right would mean minimum of 4" of sand depth in all tanks.
<Mmm, no; not necessarily. The others could have a shallow depth>
The tanks are all 31" high -- so that would take some of my usable swim height away -- beside the aesthetics and cost that I don't like.
I figure to need about 2400 lbs which would be about (60) 40 lb bags to achieve 4" in all tanks and also to have a 4" to 6" DSB in the sump refugium chamber.
<Just try the latter>
I am going to use Carib sea Fiji pink reef sand with granule size per Carib sea site between .5 mm to 1.5 mm. This thus gets me some granules of sugar fine grade and some of medium grade per Anthony Calfo's grade system on WWM. I was going to mix the Fiji pink with Carib sea sea flor special grade reef sand to get some bigger pieces (Carib sea website says 1.0 mm to 2.0 mm granule size for special grade sand) but decided that mixing the two types was not indicated per WWM and that special grade granule size would be too big for DSB to work right?
<For optimal function, yes>
I elected not to go with the sugar fine Carib sea as my LFS does not have it to start with -- and this is too big a set up to have the 2 year half life of that particular sand from what I read that it will dissolve to half -- and to have to add 50% more volume in 2 years was something I did not want to pay for / have to do.
So -- do I need 4" if I am going to use sand and don't want to use just 1/2"? Thank You!

In the refuge chamber - -is sand good enough --- or do I need to use mineral mud too?
<You don't have to>
There will be a big skimmer in another chamber in the sump.....Also live rock in the sump besides all the tanks will also have live rock. The tanks will all be reef tanks in this set up downstairs I forgot to mention.... The LFS sent me home with 3 gallons of mineral mud for the refuge chamber and told me to mix it in with the sand. I did not to it -- I just used sand....This OK?
<Yes; though the mineral mud won't hurt anything>
Not sure what type of macroalgae I will use yet -- need to research that still.
<Good. Read here: http://www.wetwebmedia.com/refugalgfaq2.htm
Lastly: I have read about all the QT methods on the WWM site. I have never personally had a fish tolerate a FW dip -- so I don't try it anymore - they get too stressed...Everything that the LFS sells is parasite ridden.
My water from the tanks that have been in operation for 3 years upstairs undoubtedly has some level of Ich or other parasites in it -- as the fish have all had Ich at some time or another -- either when they were added or when a new fish was added -- and iched everyone out. These fish are all 3 years old and they are beautiful specimens --- there are like 20 of them.
They exhibit no signs of parasites now -- but likely they could be carriers.
<Likely; but with immunity of sorts>
Before I take these fish out and bring them downstairs to their new tanks -- do I need to QT them or put them in a medicine tank?
<No>
I have both types of these tanks running now -- a 110 Qt tank and a 55 medicine tank that has had copper in it. I just feel that moving these fish twice -- i.e.. from upstairs to QT then to new displays could kill them from stress.
If I move them straight to the new tanks -- I would guess I would then have Ich in that new system water?
>So?<
Then -- even if I QT / medicate all new fish coming in after them -- and they come in healthy to the new display tanks -- once they hit the new tank display water -- they could Ich out -- as there would be Ich of some form in there from my 3 year old fish introduction?

It would take a very long time to get all 20 fish through QT and into the new downstairs display tanks -- as currently they reside in 3 separate tanks upstairs and all could not go through QT together at same time -- and these 3 year old fish and these old tanks need to exit the room they are in upstairs and get into the new tanks downstairs ASAP -- as this room they are in upstairs needs to be turned into a bedroom -- and these tanks they are in upstairs will be sold back to the LFS soon after
In reality -- what is the likelihood that a piece of Liverock or a coral or a fish in the future that went through QT and all the best practices would not end up with one parasite on them anyway == somehow that slipped through -- and would inflict the main display anyway?

 Then I went through all the work of QT the (20) 3 year old fish for no reason and maybe even would loose <lose> some of them from all the stress?
I don't know = I want to do it right.....
Thanks!
David
<All a matter of degree... like most all the universe. Congratulations on your new basement systems. Bob Fenner>
Re: New 1000 gallon set up: substrate question and how to move 3 year old fish to it 1/2/12
Hi Bob -- I am so excited to have had you answer my questions and hope you are having a good new years day. Just a couple follow up points /
questions and then I will let you enjoy your evening.
1) sounds like having a 6" DSB in the remote 300 gallon sump (will be about 400 lbs of Fiji Pink to achieve this depth in the refuge chamber) will be sufficient to achieve some Natural Nitrate reduction. If I employ the 4" depth in all display tanks too -- will that benefit me a whole lot more for nitrate reduction than just doing it in the sump == or not to a great degree that it is worth all the money and not enjoying the looks of it?
<Not in my opinion, no. Again, unless the life you place needs deeper, I'd settle for a minimum of substrate elsewhere>
I will have all displays stocked full of live rock as well as the sump.
(Besides a top of the line skimmer -- I really don't want a lot of machines running to dose things....I want to keep it simple and natural with macroalgae and water changes as my main tx's. If DSB's in all displays are going to be a wonderful way to assist me in keeping the tanks healthy and as maintenance free as possible -- I would do it).....
<Understood>
2) In the display tanks -- you mentioned I could use a shallow or aesthetic depth. What would that be? 1/2" to 1" ? ( I am afraid I don't like shallow look either -- I like the 2" depth look ..... :(
<Less is better>
So in the displays -- is it either I pick a shallow depth or go with 4" ( or higher) -- but no in-between depth?
<Ideally, yes>
2) You mention that I did not need to buy the 2400 lbs of sand -- if I had "other means of providing biomineral and alkalinity... and your livestock doesn't require such..." I am not sure if I will have other means going -- I will have all the tanks and the sump stocked with live rock -- does that cover me for the biomineral?
<That and salt mix change-outs, likely so. You should test... determine if the biomineralizing life, metabolism here, and reductive events in these systems need "boosting" w/ supplements, reactors>
As far as the alkalinity -- I have to dose now upstairs tanks every day for KH. I use Instant Ocean /IO reef crystals....Will DSB's eliminate the need to have to dose KH so much?
<Only time, measure can/will tell. Should be much less for a considerable period of time (months to years)>
These upstairs tanks are reef tanks too-- just as the downstairs will be.....Does a DSB help with having to buffer for KH so frequently?
<Oh yes>
Thanks Bob. I appreciate it!
<Certainly welcome David. BobF>

DSB with seahorses 10/2/11
Hi Crew,
<Alex>
Sorry if this question has already been answered anywhere on your brilliant
site, but after some extensive scouring I've not found a direct answer to it. I'm looking to set up a tank for some seahorses and was thinking of including a DSB to aid with water quality, this leads me to two questions.
The first of which is that your FAQs on DSBs suggest that high flow rates are necessary to keep a DSB healthy and functional.
<Mmm, not too high, just no "dead spaces"... sufficient and complete enough to have some "above substrate" water movement everywhere>
Conversely seahorses
require a low flow, does this exclude the pairing of the two in the same tank?
<Not IMO, no>
Secondly would you say it is necessary to include a DSB as I plan on including a large sump with large quantities of LR?
<Mmm, not necessary... but/and can be situated in the sump...>
The main tank could potentially be as large as 210 gallons with several pairs in.
<Mmm...>
I have seen it mentioned that you can have a tank that is too large for seahorses due to the difficulties in maintaining prey densities.
I can only get hold of WC horses for the moment, so will need to feed them live food.
<Mmm... I strongly suggest you make even Herculean efforts to secure captive-produced stock (vs. wild-caught). REAL troubles w/ the wild... disease, acclimation and food-provision wise>
Many thanks
Alex
<As many welcomes. Bob Fenner>

Plenums, DSBs, and Science 5/3/2011
Hi guys. I was recently referred to an article that in turn cited another article, "An Experimental Comparison of Sandbed and Plenum-Based Systems. Part 1: Controlled lab dosing experiments," by Toonen and Wee, in Advanced Aquarist. My conclusion after reviewing T&W was quite different from how they characterized their results:
<This: http://www.advancedaquarist.com/2005/6/aafeature/view?searchterm=None>
"The problem with this article is not in the experimental design per se but in the statistical approach. Leaving aside curious results of Bartlett's test (from what I can tell, the significant p-value showed that variances were not homogeneous), the problem is that you really needed to do a formal survival analysis, focusing on the rate at which ammonia and nitrite were brought down to zero. The time dimension was absolutely critical, and all we have now are some plots that are suggestive. My conclusion is that a deep [coarse] sand bed with a plenum appears to be preferable to other combinations. By the way, nitrate levels are not stationary over time. It seems that the plenum approach is more resistant to nitrate buildup within 30 days. This is important, as water changes in good real-world tanks certainly occur at least once per month."
<Actually, the experimental design does leave some things to be desired.
For instance, the use of ammonium chloride as the inorganic feeder source of ammonia. We can discuss this and other alternatives if you care. I don't come to the same conclusion as you re the preference of coarse and deep sand bed w/ a plenum on the basis of the data presented, nor the "resistance" to NO3 accumulation w/in the model's time. The experiments done, the data presented do not significantly/statistically affirm/confirm these statements. What is of use (other than the null-hypothesis that neither depth nor presence of a void space/plenum is of more utility than a pure sediment-filled space, is pointed out: finer, deeper substrate is of more use (likely due to greater solubility/buffering capacity) than coarser and less deep. None were superior in terms of greater nitrogenous conversion>
This article seems important. What is your take on it?
<Other than the aforementioned, the "bonus" finding re the use of finer sediment and insolubilization of phosphate. This study is principally valuable for what it does not confirm; that plenums are more desirable (w/in the limits of the experimental variables employed), than substrates sans plenums.>
Best,
Sam
<And you, Bob Fenner>
Re: Plenums, DSBs, and Science 5/4/2011
Very interesting, Bob. When I referred to the experimental design, I meant the use of repetitions within a factorial design.
<Understood>
Your point about the source of ammonia would not have occurred to me.
Indeed, come to think of it, a number of decisions made in the experiment may make inferences to real aquariums problematic (e.g. while I read the non-statistical parts quickly, wasn't the "fine" substrate play sand, and isn't this quartz?).
<The "newer" one is... years back, this hardware (Home Depot) product was largely calcium carbonate of sea origin>
My issue was that statistically insignificant differences over a long period (111 days?) seemed to be the take home point.
<Agreed>
And yet, from my reading, isn't it true that the speed with which ammonia and nitrite are converted to nitrate is very important?
<Mmm, can be, yes>
There is a saying that in the long run we are all dead.
<S'truth>
Yet the issue of speed cannot be addressed with the ANOVA used in this experiment. The only exploration of rate came in a series of plots over time with various combinations of factors.
<Yes, the utility of analysis of variance tests/testing>
What we do not know is whether these differences in the rates of conversion of ammonia and nitrite are statistically significant.
<Which they were not here>
From my reading here, I know that many conditions in the aquarium are important, not just ammonia and nitrite. However, these two conditions are vitally important in the short run. Have I missed something?

As for nitrate reduction, again we cannot judge the rate of reduction with confidence from the plots. My eyeballing seemed to suggest, however, that nitrate buildup occurred slower in the deep/coarse/plenum situation, even if it ended up at the same place at the end. If so, then water changes would not need to be so frequent or substantial.
<Depending on accumulation values>
I wish that they had done a survival analysis with the endpoints being zero ammonia and nitrite, and high buildup of nitrate.
<Time and other limits...>
Finally, I do not know whether any of the time-based differences would have appeared if the ammonia dosing was less extreme. Therefore, it is not clear whether real aquarium situations can be informed by this experiment.
<Only successive approximations>
Best,
Sam
<And you, BobF>

Question concerning DSB or MUD filtration, 12/19/10
To whom it may concern,
Hello my name is Justin.
<Hello>
I am currently serving in Afghanistan as an infantry soldier.
<Stay safe.>
I only say this to say that I have very limited access to the internet and would hopefully like a quick response. That way I can read whomever answers thoughts.
Anyway my question is concerning what I have been reading about these filtration systems. My question might sound outlandish but it kinda sounds similar to a compost pile to a garden?
<Not really, they are more about getting pollutants, nitrate mostly, out of the system. We don't really want them to release nutrients back into the system.>
That is another hobby of mine and that's why I am asking. And if this line of thinking has no truth to it, is it maybe at all possible to make a "compost pile".
<It would cause all sorts of problems in a closed system like an aquariums.
Too few nutrients are rarely a problem in tanks, more often too many nutrients are a problem.>
Like in the sense that just so many of use (aquarist) dose the systems with outside supplements. Is their a way to do this more naturally or I guess I should say through a more "natural" processes?
<Not really, there just isn't enough room and reactive materials to maintain levels of beneficial chemicals to support the livestock, especially without letting toxic conditions get out of hand.>
As I'm writing this I think I am starting to somewhat answer my own question. in the sense that if their was or is a way possible it is being worked on or trying to be figured out... anyway I still would like some insight by whomever answers this.
<Nutrient control is usually a bigger issue in aquariums than a lack of nutrients.>
Also if it is being worked on or trying to be figured out can I be pointed in the right direction possibly to read up or learn about these techniques?

Hopefully my question makes sense, and if I have already found the place to look for this information I guess patience and experimentation are on the order. Thank you to whomever answers this
kindly,
Justin
<Welcome>
<Chris>

Extreme Phosphate & DSB Question/Phosphate Control 8/8/10
Hi WWM
<Hello Malcolm>
I have a big problem with Phosphate. Measures 1.8 on a Hannah meter and the Salifert PO4 test backs this up.
<Yikes.>
Ammonia, Nitrate and nitrate all are 0
<At least nitrate is under control.>
Some background, the system is about 3 months old. It comprises a lot of 'stuff' (sand, rock, water etc) from two other tanks I have and from other donor sources so its not a new virgin system with all the major startup issues. No ammonia spikes have ever been detected so I think everything from the other tanks is doing its job.
In an effort to isolate the phosphate source, I have been removing things and putting them back in the other tanks, hardware has been soaked over night and the water measured. Apart from a little leeching from one PVC hose and some of my home brew food, I've found nothing.

I'm now down to a display containing some shrimps, a Banana Wrasse, a heap of coral.(All the rock without coral has been relocated), 1" of sand, the sump and of course the PO4.
The sump which incorporates a fuge and DSB. Both areas are about 12" x 16" x 16" high. The DSB is about 8" deep with very fine sand.
The media for the DSB came from a friends setup who closed it down so as to travel overseas and he had no issues with it. I've since topped it up with fresh clean virgin sand by about 2" to get the 8"
The sand was transported in a few different layers so that I could try and retain as much 'life' as possible after relocating it all. The layers went back in in the order they came out. Naturally a massive sulphur stink but WWM advised that the DSB should sort itself out. Apart from the Phosphate problem, everything is going well.
To cut to the chase. Could my DSB be the source of the Phosphate?
<It could to some degree depending on it's contents. I'd suggest placing Caulerpa
in the fuge to aid in lowering the phosphate level.>
I do a 10-15% water change weekly.
<Great, does help.>
Dosing with Prodibio products and Vodka has had no sustainable effect.
I've just bought a RowaPhos reactor which will be installed next weekend.
<Another good move and would recommend the RowaPhos media as well.>
Should I remove the DSB media, wash it all out and start again?
Obviously I do not want to do this as it will take months to re-establish but the Phosphate is promoting way too much algae.
<No, I would not. There are other ways of controlling phosphates as mentioned above and forthcoming below.>
Is this possibly another part of cycling which I've not experienced before. In my experience 'seeding' with so much media from the other tanks should have removed most of that issue. Should I just leave it alone for a month or so more and see if it sorts itself out?
Your thoughts please
<I'd like to start out by saying that Phosphate is one of the top 14 out of 70 trace elements found in natural sea water that are known to be essential for fish and reef tank systems. It is also a primary nutrient source for algae, particularly green hair species. Phosphates can be introduced in several ways. Using unfiltered tap water for making up sea salt mixes or as top-off water, some salt mixes, activated carbon, KH buffers, and foods put into the tank.
Now a few suggestions to reduce phosphate levels in your system. As you mention above, a phosphate reactor, employ a Polyfilter pad, and the use of limewater and/or Kalkwasser for your calcium additive. Adding a limewater or a Kalkwasser solution has been known to reduce phosphate levels. The following quote from a Sea Scope flyer states, "One of the theories why calcium hydroxide might produce better results than calcium chloride has been that the high pH and high calcium in a saturated calcium hydroxide solution cause precipitation of phosphate from the freshwater, eliminating this algae fertilizer from the solution." Further reading and suggestions can be found here.
http://www.wetwebmedia.com/phosphatemar.htm>
Regards
<Ditto, James (Salty Dog)>
Malcom
(Australia)
Re Extreme Phosphate & DSB Question/Phosphate Control 8/8/10
Many thanks for your reply.
Some additional comments inserted below-
<Mmm, in future replies, do not insert into the original text, just reply to the original thread. Makes it easier for us to read/reply. I will cut/paste your "insertions" below.>
I do have Caulerpa in the fuge adjacent to the DSB. I'm not noting any explosion in its growth. The Hair Algae is having too much of a party.
I am using RO water for top ups etc. It measures 0 for PO4 as does the NSW I use.
<Great, that suspect is eliminated.>
Polyfilter pad is a new one for me. Google here I come.
<Have been around for ages and a good multi-purpose chemical media.>
I have a Kalkwasser reactor but haven't plumbed it in yet. I wasn't aware of its phosphate reduction abilities so just its moved a lot higher in my priorities.
<OK>
Many thanks James.
Appreciate the support.
<You're welcome. James (Salty Dog)>
cheers
Malcom

Due to an upcoming move I have been thinking about adding a deep sand bed to my saltwater tank. 2/16/09 I have two Engineer Gobies, and two Dusky Jawfish who seem to tunnel everywhere they can. <What they do> Because of this is there any benefit from a deep sand bed other than for the burrowing of the fish? <All sorts... I say... go on and add the DSB Kevin... with at least a couple areas with some "rubble" mixed in to stabilize your burrowing fishes' activity. Bob Fenner> Thank you
Kevin

DSB for Each? 8/2/08 Hello everybody, <Ramon.> Let me start off by saying I am glad that there is a site like yours that can give an individual the chance to first do research on their part and then ask if it can't be found. <It is the principle.> Its shows how much that person really want to excel in this vast hobby and with all the combined knowledge that you and your partners have to give to us it is truly a gift and I thank you for that. <Thank you for such and endorsement!> My set-up is a 55 Gallon Tank (not drilled) with 60lbs of LR and 2 in. of LS has been set-up for 6 months but transferred my 29 gal. into it and it was set-up for a year. I also have a 15 Gal. Refugium that is a Rubbermaid which has been set-up for 3 months now has 15 lbs of LR and 1 in. of LS it comes on the system lights are off; it also has a small piece Chaetomorpha in it. The light is a single twist bulb that is 65K. <Sounds like a nice, practical setup.> My Sump is also a 15 Gal. Rubbermaid <Love it!> that has been set-up for 3 months also has been not split into sections it contains my protein skimmer getting a new one) and heater, I was planning on putting 15 lbs of LR and a light source in here, what do you think? <Yes on the live rock if you wish, I would skip the lighting unless you intend to grow a macroalgae here too.> The Refugium and the Sump and being feed by a Maxi-jet 1200 'Teed' off so that the Refugium gets most of the flow and then gravity feed into the main tank. I am planning to do a 'closed loop system' or a Tunze TurbelleÂ® stream Kit TS24 which one would be the best? <I am a huge fan of powerheads instead of closed loops. Powerheads just provide the flow without the high ongoing energy costs associated with closed loop pumps. The Tunzes are a fine choice (with this kit you will need to turn them down a bit), but do also look at there NanoStream line, the Hydor Koralias and MJ mod kits. If you plan on a much larger tank in the near future the TS24 kit makes sense, otherwise it is a lot of money to get some flow.> I also wanted to know if I should make a DSB for my Sump/Refugium/Tank. Or should I just add 1 in. to my sump to make the whole system 4 inches? Ph: 8.07(am) and 8.15(pm) ph controller SG: 1.021 <Do consider raising this to 1.025-1.026.> Temp: 79 N03: 10 ppm N02: 0 Tank members are: 1 Cleaner Shrimp 1 Button polyp colony (size of a dollar bill) 1 Unknown (might be a Pistol shrimp or Mantis shrimp, I hear it but don't see it) <You will find it in time.> I do a water change twice a week 2.5 gals. And dose (Kent Marine Iodine, concentrated and Strontium & Molybdenum) daily, I and also in the process of getting a calcium reactor. <Ca reactors are a nice addition in a populated tank. As for the dosing, do you test for these? Your water changes should be plenty for these elements.> Thank You for your help Ramon, Tampa FL <Welcome, have fun. Scott V., Fresno, CA.>

Re: DSB for each? 8/2/08 Thanks again for your reply, <Welcome.> I will be adding 3 in. to my Refugium and 2 in. to the main tank. <Sounds good.> Do I add an half an inch every week in the Refugium first until I reach my depth and then my main tank after? <This is a safe, good technique.> I also wanted to know should I clean the bottom of the Sump before I add the LR or just leave it? Thanks Again, Ramon <Welcome, Scott V.>

Question about Application of DSB to Increase Bio-Diversity in SPS Tank -- 07/21/08 Hello WWM Crew, <<Hello Scott>> I wonder if I can get your input regarding a decision I made recently to convert my (two years running) 135 gallon SPS system from a shallow sand depth to a DSB? <<Certainly>> The display contains roughly 120 lbs of live Kaelini rock. The circulation rate through the sump is about 1300 GPH, which I have since increased rather dramatically by adding four EcoTech Vortex pumps. <<Excellent>> Filtration consists of an Ecosystem 3616 Mud Sump with some Chaetomorpha (in addition to lots of other types of competing micro algae) and roughly 25 lbs Live Rock. The mud sump also houses an Eco-Reef CS 135 (which consistently produces dark skimmate) <<'¦!? Do you mean a Euro-Reef CS135?>> and four (1 cup) bags of carbon of which one bag is changed weekly. Water parameters are good, with pH around 8.3 and ammonia, nitrite and nitrate not detectable per Salifert test kits. I keep the aquarium relatively lightly stocked with the following fish; Flame Angel, Bicolor Blenny, Purple Tang and Sunrise Pseudochromis. The system is also home to a Blue Legged Hermit Crab, about 6 Astrea Snails and a Serpent Star, along with three small Acropora, two Montipora and a Pocillopora SPS. Thanks to your help, these animals are thriving. <<Is good to know>> In addition to the above, it has always been my goal to develop a system with the maximum level of biodiversity possible under the circumstances and have relied heavily on "Reef Invertebrates" by Calfo and Fenner (along with your outstanding website) for guidance along the way. <<Some good reading for sure>> As part of this strategy, I try to 'rotate" about 15 lbs of fresh (8 weeks cured) rock to "seed" the mud sump every couple of months with new life. <<An excellent practice'¦ Bob has often touted 'replacing' a portion of the rock in one's system on at least an annual basis for this purpose and too help replenish buffers/biominerals that do get 'used up' from the rock>> In spite of my efforts find that I don't get the level "critters" (copepods, amphipods and other types of desirable LR hitch hikers) that I am trying to foster and thought a DSB might be appropriate at this time. <<Mmm'¦a deeper sand bed may help with these particular critters by a small measure'¦but for critters such as amphipods and mysids, a course matrix like the Chaetomorpha macro-algae and the rock rubble is a better 'producer' of such in my opinion. If populations are not what you think they should be it is likely you need to 'feed' your refugium (I like inexpensive and easy to use shrimp pellets for this). Don't get me wrong, I am a big fan of DSB methodology and I think it will be a great addition/benefit to your system'¦just don't expect an explosion of amphipods and mysids from simply increasing your substrate depth>> When I initially set up the system, I decided against using a DSB because I was new to reef systems and was not sure I could maintain this properly. Instead, I opted for a 3/4" sand bed using (0.5 - 1.0 mm) aragonite. Over time, my husbandry skills have improved and with the recent addition of the Vortex pumps, accumulation of detritus is kept to an absolute minimum so I just added more aragonite to obtain an average bed height of about 3-1/2 to 4 inches. <<Okay'¦sounds fine>> The heavy agitation by the pumps is a mixed blessing. <<Ah'¦yes indeed>> While the high flow does keep detritus in virtually continuous suspension, it also has the affect of creating some very dramatic "hills and valleys" in the sand. To the extent that some areas of the tank are shallow (say 2" depth) and others are quite high (around 6"). <<I do understand'¦ I have a 7' sugar-fine DSB in my display along with seven Tunze Stream pumps of varying power/flow rate. The key; and the challenge, is in arranging/positioning the pumps to minimize disturbance of the sand bed. Some 'movement' is inevitable (especially when/where flows converge), but I find positioning the pumps as high/near the surface as possible still allows for very good flow throughout the tank while minimizing movement of my substrate>> I have attached a photo for your reference, which shows the lower lip on the cabinet which covers the bottom 1" of the sand bed. <<I see it'¦ That's some extreme movement for sure'¦and not conducive to the true function (Nitrate reduction) of the DSB, in my opinion. It does also appear from the picture that at least one of your EcoTech pumps is positioned quite low in the tank. I suggest you move these to the top of the tank and see how things go>> I am at a point now where I am reluctant to add more sand as I don't want to reduce the water column height any further. Based on your experience and expertise, would you please advise your thoughts; have I stumbled into an "intermediate" zone that will achieve neither of the benefits of a DSB or a shallow bed? <<More the former if the bed is in a constant state of change'¦and maybe even becoming problematic over time if/when certain elements are 'bound-up' but later released by severe movement of the substrate>> Can the above setup help to improve biodiversity if one is careful to insure that there is an absolute minimum of detritus accumulation on the sand bed? <<I don't understand how you are making this correlation. Many of the critters that inhabit the substrate are'¦detritivores. As I alluded earlier'¦low population density of these animals is likely directly related to the availability of foodstuffs'¦to include detritus. I don't mean to send mixed signals as we all know detritus 'accumulation' is to be avoided. But continually blowing your sand around (whether shallow or deep) as much and in the manner your photo depicts will not be conducive to fostering substrate biota of any kind. If you can't or don't want to reposition the pumps to minimize shifting of the substrate'¦I suggest going back to a sub-1' depth (for aesthetics, mainly) and concentrate on boosting the biota in the refugium with regular feedings>> Thanks in advance for your reply. Scott <<Happy to share. EricR>>

GHA and DSB multiple choice, 6/26/08 Hi Folks, <Hello> I have been battling green hair algae in my 38-gal reef tank for about four months, and the algae is winning. Tank footprint is 36" x 12". Turnover is about 21X per hour. I run a HOB filter with carbon, and squeeze out the pads in a bucket of tank water every couple of weeks. I also run a Remora skimmer which is pulling out mostly clear water lately. <The algae is doing a good job of scrubbing your water clean I would guess.> I have about 50lb of live rock. I change about 5 gal a week. Tank KH tends to be around 9; LFS said getting it up to 11 or 12 might help. <Might a little, but probably not appreciable.> Inhabitants are a pair of Ocellaris, a Royal Gramma, a Coral Beauty, <Will need a larger tank in time> and an Algae Blenny; torch, hammer, and frogspawn corals, a trach, a bushy-type Sinularia, and a finger leather of unknown species. A couple of months ago, I discovered that I had about 20ppm nitrate in my well water, so I bought an RO unit, to no effect. <Will at least limit nutrient input into the tank over time.> The salt mix tests negative for nitrate and phosphate. I've begun to drain off the liquid from my frozen foods. <Good, and you may very well need to cut back on feeding.> My light bulbs are only about 6 months old. When I remove the algae manually, it comes back with a vengeance within a week or two. <Nutrient fuel is still being added to the tank somehow.> Now, I do have my rock piled in such a way that gunk tends to collect in one corner. I plan to rearrange my water flow and add another water pump to address this. However, I've also read quite a lot on WWM re: DSBs recently, and I seem to have the infamous 3" of substrate. <Not very helpful for nitrate reduction, but should not be driving the algae bloom.> I'm thinking maybe I should try to add another inch. <Would help for nitrate reduction, but probably not effect the algae growth much.><<RMF disagrees>> Should I: A) pour the new substrate right on top of the collected detritus; B) stir the gunk back into circulation first, then put the new substrate in; <Could, but won't make a big difference in the long run.> C) tear apart the rockwork and vacuum the stuff out first; or <If it helps you pull out more algae might be worth the effort.> D) none of the above? What else am I missing? I'm getting pretty discouraged. Thanks, Scott <Sounds like you are doing most things right so it is a matter of finding out what is driving the algae growth. I would be it is overfeeding, many hobbyists can easily 1/2 the amount of food they add to the tank and the fish will be fine. Try doing this along with your current actions and see if it helps over the course of a few weeks.> <Chris>

Bare Bottom or Shallow Sand Bed (DSB!) -- 04/14/08 Hey Crew, <<Hey Danny>> I have been running my 65 gallon reef tank bare bottom for 5 months now. In it I have a few soft corals, some Zoanthid frags, a few mushrooms, a frogspawn LPS, a clam, 2 clowns, a solar and Sixline wrasse, a flame angle and a cleanup crew of about a dozen snails and a few hermit crabs. I have about 85 lbs of live rock, a protein skimmer, Aquazone-Plus Ozonator, Filstar-2 filter running with both carbon and Purigen, 2 Koralia-3 power heads (facing each other to create random flows as recommended on WWM - thanks), dual 150w 20k MH along with a T5 and moon lights running on timers. So far everything has gone well now that I seem to be past my initial algae blooms for a few months and have yet to have any loss of life other than a few snails and a couple of hermits. Now, as I continue to learn by reading on WWM, books like the Conscientious Marine Aquarist along with countless hours of discussion with my LFS and other aquarists, there still seem to be no definitive answers to the substrate debate. <<Indeed>> It all seems to hinge on the bare bottom's allure of easier detritus removal by vacuuming during weekly water changes and occasionally blowing it out from under the rock with a power head versus the shallow sand bed benefit of added buffering and some additional denitrification / beneficial life forms. <<That, and one's sense of aesthetics'¦it's 'some type' of substrate for me>> My main concern is long term system viability that requires a realistic maintenance routine however; I am not considering a DSB for my 65 gallon system since I don't want to lose that much space. <<Understandable'¦perhaps remote>> One potential win-win could be to have a remote DSB in a sump added to my system in time... <Ah, yes!>> Since the best part of this hobby is musings, the learning process and discussions it spawns, I continue to have many more questions than answers... so; I turn to you guys to add your expertise to the experience! Danny <<Well, Danny'¦I am a HUGE fan of DSBs'¦ I have employed most every 'style' of substrate methodology in more than three decades of keeping marine systems (to include under-gravel filter systems!) and feel I have been most successful with the DSB methodology. But'¦the proof is in the pudding'¦as they say. If you are happy with the look of your current methodology, and it works with your husbandry/maintenance style'¦why change it? EricR>>

Nitrate Levels And DSB -- 11/29/07 Hello fishy-gurus!! <<Hee-hee! Eric here... Not so much a 'guru' as just a long-time hobbyist willing to assist/share my observations and opinions>> I got a few questions regarding DSBs and nitrate levels. <<Okey-dokey>> I have a 430 Litre reef system, <<Mmm, okay...about 113-gallons for those readers on 'this side' of the pond>> 5cm of sand-bed (consisting of crushed marble and aragonite CaribSea sand sugar fine grade) and nitrate levels of over 40 - 80 permanently. <<Yikes! Much too high, as I am sure you are aware. Just off-hand I'm thinking either reducing the depth of your substrate by half, or preferably, increasing the depth about three-fold should effect a change/reduction in Nitrates >> I'm using the Berlin system with about 25kg of live rock. Other than that there are two Aqua One powerheads pumping 2500 and 2200 litre/hour and one Rio powerhead of 2000 l/h which is attached to my Aquasonic Venturi Skimmer. Because I have a chiller I had to connect an Aqua One Canister Filter (500L/H) to it, which contains Sponge and noodles. <<Ah! A clue maybe! If you are not cleaning this canister filter media 'at least' once a week then this is likely the source of your Nitrate issues due to the decomposition of the accumulated detritus>> My inhabitants are: 1 yellow tang 2 maroon clowns 1 damsel 2 lawnmower blennies 1 white ribbon eel <<Pseudechidna brummeri? Hmm, have you had this creature long? Though maybe not quite as 'touchy' as the Rhinomuraena species...is still thought to be a difficult animal to keep>> And 2 redline cleaner shrimps, heaps of corals and hermit crabs and one huge anemone. <<Mmm, not a good mix...I hope the Actinarian doesn't decide to go on walkabout...>> I do water changes every two weeks of about 100 - 140 litres. I just read all I could on DSB on your website but do have the following questions: 1. If I want to add another 10 cm of substrate would it be ok to go half and half with CaribSea Aragonite and the other half of natural Ocean Sand (I live in Australia/Queensland on the coast). <<It's not usually suggested to use 'beach' sand due to the possibility/probability for introducing harmful elements/pollutants. But, if you are certain the sand can be collected from a clean source there's no reason you can't do as you outline. You might want to also consider treating/curing the sand just as you would newly collected live rock>> Other than the fact that the sea sand won't do much for my pH levels and the potential danger of introducing pathogens, will it do the same job for NNR? <<It will... Just as buying some sand from your neighborhood hardware or home store would>> 2. I read somewhere on you site that you mentioned that the canister filter would have to be cleaned regularly because of the filter media in it. <<Yes>> Does the media inhibit NNR? <<It doesn't 'inhibit' the process...but not cleaning the filter can allow nitrogenous compounds to accumulate faster than the DSB can process them, thus 'overwhelming' the process of NNR>> If this is so, I could just run the canister filter without any media in it!? <<Indeed...but why waste an opportunity? I suggest you use this filter to hold a 'chemical' media such as carbon or Poly-Filter...to be exchanged on a bi-weekly basis>> 3. What is the ideal amount of rock to have in my tank to help NNR? <<Hmm...whatever amount is necessary to render a Nitrate reading of 'zero' for the size and stocking density of your system and the quality of the rock used, along with your particular husbandry skills and maintenance habits... I don't mean to be flippant, but only you can really determine what amount is going to work through testing and experimentation. My preference is to minimize the amount of rock in a system to allow room for growth of the corals and freedom of movement for the fishes, and utilize a large DSB for Nitrate reduction>> 4. How much would you siphon through the DSB to keep it working perfectly? <<Sorry...you will need to clarify this>> 5. How is it that I am battling with such high nitrate levels and yet all my corals are doing well/growing and the cleaner shrimps are perfectly well, too. <<Well...are you certain of the efficacy of your test kit? I suggest you try testing with new/different brand kits to validate your readings. Perhaps your Nitrate 'problem' is not as it seems>> I've got the beginning of the year. The anemone was a white colour with pink tips when I purchased her, <<Bleached>> she is now completely purple. <<Excellent>> Is she busy dying? <<It would not seem so>> I thought I works the other way around, they start of purple and turn white before they die? <<Indeed>> All my live rock is also covered in purple coralline algae?? <<Sounds good>> Ammonia and Nitrite levels are Zero, pH forever 7.8 - 8.0. <> I'm struggling to raise it above 8.0 even when adding liquid aragonite regularly!! <<Hmm...do let me know your calcium and alkalinity readings and we can pursue this further...and do say what this 'liquid aragonite' product is as I suspect it is not of much help re>> 6. Do hermit crabs and other crabs add to your bio-load as fish do or are they beneficial (clean up crew) and therefore the more the better? <<They do add to the bio-load, as does any living organism. They can be beneficial and, depending on your point of view, they can be a bane. I do not keep hermit crabs due to their 'very opportunistic' eating habits, and I consider the commonly used Astrea snail to be more trouble than its worth...but...the vast majority of hobbyists do employ these critters as a 'clean up crew'>> Lastly- 7. One of the guys at the LFS advertised the Eco-System with Miracle Mud as so good that he hasn't done any water changes for 6 months and all his levels are ideal. <<No such thing as a magic-bullet... Regardless of the methodologies used, I'm a firm believer in regular partial water changes>> Have you heard of that and does the Eco-System reduce nitrate levels. <<I've not used the Eco-System methodology myself but have heard much good about it. And the owner/perpetuator of this system is a good and much respected friend of Bob's>> If I install one, can I have it running in conjunction with my Berlin system and 15 cm DSB? <<Certainly... I think it is a very good idea to have this or any other type of refugium methodology employed with any marine system>> Also would it work to add Miracle Mud to my canister filter without light and algae growth? <<No... The mud would prove to fine/would likely only cloud your system>> And sorry this takes so long, if I don't want to drill holes and go the whole way, would it help to purchase a hang on Eco-System (not big enough for my system) and run it with the Berlin system? <<Would still be of some benefit, yes...but much better to employ a larger vessel under the display tank...in my opinion>> I appreciate all your suggestions and really would like to sort my tank out. thanks so much in advance. Best regards, Jana <<I'm happy to help, Jana. Eric Russell>>

Deep Sand Beds, Live Sand, Biodiversity 11/19/07 Hullo :) <Hello> I have a question regarding DSB. <Ok> I understand for a DSB to really be a NNR instrument, it needs the small creatures (worms, pods) to colonise it. <Yes helpful, but the NNR is done by bacteria, not microfauna.> However, I also know that by the time we get the sand from the beach (best form of LR) <Not necessarily, the potential for contamination by pollution or undesired organisms is quite high in most sand collected from beaches. I prefer a little cultured sand on top of "dead" sand or just letting the Live Rock seed it.> it will have a fraction of the bio diversity in it. <Yes> Is my understanding correct? <Mostly, but it depends on where this thinking is taking you.> Cheers Ranjith <Chris>

Re: Deep Sand Beds, Live Sand, Biodiversity 11/19/07 Hiya Chris, <Hello> Thanks for the quick response. <Welcome> The reason for the question was whether just taking construction sand and seeding with Live rock will help me accomplish the following: 1. Keep nitrates under 5ppm (bottom layer) 2. ensure ammonia and nitrite are zero (top layer) Cheers Ranjith <I have to admit I'm not familiar with construction sand, but as long as it is calcium based, of the right size, and free from chemical additives it should work nicely for what you are trying to do here. Given time the LR will seed the sand with all sorts of life.> <Chris>

Plenum or DSB/Backup Power -- 06/30/07 Hello crew. <<Howdy Eric'¦EricR here>> I'm in the midst of planning a 125g mixed reef setup and have a question about whether or not to employ a plenum layer. <<Okay>> If I were to have an Aragonite sand bed of <1", would I be good (in terms of keeping nitrates to a minimum) with not using the plenum? <<Hmm, have you read any of Bob Goeman's writings on plenum methodology (here's a place to start: http://www.saltcorner.com/sections/guest/goemansandgamble/sandbedspart1.htm)? Whether going with a DSB or a plenum system, a sub-1' sand bed is going to do little for 'direct' Nitrate reduction>> I am planning to use a 30g sump, and if I were to go the DSB route there, would I use a plenum layer?? <<Is up to you'¦I prefer simply to go the DSB route>> Oh, and I have one more question regarding backup power--aside from something like a generator or a Yugo battery, are there other more convenient options for a tank of this size that you'd recommend? <<There 'are' battery-backup systems available'¦most designed as backup computer power. I find these expensive and of limited utility re hobby use'¦though admittedly I have not done any extensive research on what is available. For a system your size, a small gas-powered generator to run the 'essentials' would likely cost about as much (or less?) than some of the proprietary battery-backup systems and will provide much more useable and sustained power'¦in my humble opinion, of course>> Thanks for the education and terrific website! Eric <<We're pleased you find it of use. Eric Russell>> DSB's/Coral Food -- 01/10/07 Hello, <<Hello Ronnie>> I have heard recently that DSB's are not suggested in SPS reef tanks? Any thoughts or advice? <<Hmm... I have 1000 pounds of sugar-fine aragonite in a flourishing 375g SPS reef tank, along with another 300 pounds in the in-line 55g refugium, that might suggest otherwise. Perhaps it is thought the efficient denitrification process deprives the corals of this important/required element. I have heard of advanced hobbyists adding Potassium Nitrate to their SPS systems to boost health/color/vigor. I myself prefer a heavy (within reason) fish load coupled with generous feedings>> I read Deep Sand Secrets and found a lot of great info on it. <<A good/interesting read, agreed>> I have always used one with good results. In my new 75 gallon SPS only tank, I am researching different ways to set it up. <<Excellent! I have kept myself, and have seen, many successful tanks using differing methodologies. But I must say, my greatest success has come when utilizing the DSB methodology>> Also, any thoughts on the new food line called Reef Nutrition? <<Ah, yes...am feeding the Arcti-Pods to my system now. My Anthiines seem to like it fine, as well as the other small planktonic feeding fishes. Can't really say whether the corals are feeding on it, though it does appear to be 'small enough' for several of my Acropora species utilize>> I have always used Cyclop-eeze and DT's oyster eggs and phytoplankton for feeding my corals? <<Good selections, but the phytoplankton is of little utility here as most all SPS corals will be carnivores...though it is beneficial for feeding many of the planktonic organisms/micro-crustaceans which 'do' provide a rich food source for your corals...and many of which are cultured/generated from/within a DSB>> Thanks, you guys rock. <<Thank you...thank you very much (in my best Elvis impersonation voice)>> Ronnie <<Regards, Eric Russell>>

Deep Sand Beds and Trace Elements - 10/8/06 Dear Crew: <Paul> I have read many articles praising the ability of a DSB to remove nitrogen and phosphate from the water column. I have also noted the postings that urge an adequate flow of water to prevent the DSB from accumulating detritus and becoming a nutrient sink. As a result, I have a DSB in my aquarium system with a 10x water flow. <Good> Nevertheless, here's the question that continues to trouble me: If a DSB's can import nitrogen and phosphate from the water column, how is the same nitrogen and phosphate exported from the DSB? <Mmm, a few ways...> With macro algae filters, the answer is easy: you simply trim the algae to export the nitrogen and phosphate from the aquarium system. What is the equivalent export action with respect to RDSB's? Are we to assume that garbage just keeps going in with nothing ever coming out? Thanks very much! Paul. <Similar to the algae growth mechanism, phosphate is incorporated biologically in a trophic web of chemical feeding microbes through larger life forms... And a good deal is insolubilized... converted from available phosphate to much-less solid forms of phosphate compounds. Here's a link to a nice piece re this topic by RHF: http://www.advancedaquarist.com/issues/sept2002/chem.htm Bob Fenner>

Mud/DSB/Refugium - 09/30/05 Hello and thanks for the great site and forums. <<Glad you like 'em.>> I could not link to the forums page to post there, so I thought I would send an email. Thanks in advance for your help. <<Email is fine.>> I am setting up a built-in system intended to house a live-rock based reef. My 90G show tank overflows via a custom tank top into a 55G tank converted to a three-chamber sump and returns to the main tank via a pump running at probably 1100gph (Supreme Mag Drive 12). <<Mmm...pretty good pump...but with head height, probably returning a bit less than you think.>> This custom setup was originally intended to house an ecosystem (mud) filter in the central chamber (about 20" x 12"). Over time and having read various apparently conflicting information, I wound up investing in some Aragamud from CaribSea instead of Miracle Mud. Do you know this product, and is it intended to be an alternate to MM or have I been steered in the wrong direction. <<Honestly, no...I'm not a user/familiar with either product. Though I think for the application you describe either will suffice.>> I may be confusing the functions of a DSB with a mud tank with a refugium, and what I really want to do is set it up right in the first place. <<Either will do what you desire. The finer grades of substrate just require less depth to get the job done.>> My goal is to create a system that allows relatively low maintenance - i.e., it provides filtration (denitrification and nutrient export) , it can provide planktonic food, it can reduce the amount of artificially added supplements needed. <<Oh... so you are seeking Utopia! <G> >> So is this ideal system a mud tank with just a thin layer of mud and macroalgae, a DSB with live sand live rock rubble and macroalgae, or something else? <<My preference is a 6" DSB of sugar-fine aragonite with Chaetomorpha algae. Though you could add a layer of "mud" on top of the DSB if you want.>> I have read through many of your excellent forums, but am still confused. Does a mud system accomplish denitrification? <<If deep enough, yes.>> Can a mud system support creatures that could produce the planktonic food a "refugium" can? <> Does a DSB have to be "partially changed out" like Ecosystems recommends mud systems do? <<Not so much changed out as added to. Aragonite has a half-life of about 18 mos. so you'll need to add more every so often.>> Sorry for the disorganized questions. Your advice is greatly appreciated. I have already invested $$$ in the system, if I have to invest more to set it up right in the first place, I am ok with that. <<<<Very good my friend, starting right is key... EricR>> DSB..., Denitrator, Substrate Type/Adding Snails - 08/10/06 I have decided to install a DSB in a large bucket after trying for months to set up an AquaMedic NiTRATE reductor 400, without success. It would either produce sulphur or nitrate because the turn flow valve was very difficult to adjust, making it difficult to get the correct flow rate, the drips were either too fast or too slow, it was a right pain. <<Indeed...manufactured nitrate reduction equipment always seems too "fiddly" to me, no matter which design you choose. I think you will have better luck with the DSB>> During my visits to various aquatic shops in the area, I am getting many different reasons for and against the use of DSB's, also the use of various different types of media. <<Not surprised...some folks love'em, some folks hate'em...and even among those who employ a DSB opinions will vary on application. But the basics are the same...a deep enough bed for the size granulate chosen to permit adequate stratification of the different bacterial zones>> One that has been proposed is the use of PLAY PIT SAND; have you any thoughts on this? <<I do...the "play" sand is quite suitable for nitrification purposes and will perform this function as well as aragonite sand of the same grain size...but...the play sand will not provide any buffering capacity and it is decidedly "sharper" than aragonite which "might" be rough on some of the critters which will inhabit the sand bed. The play sand will work fine, but my preference is sugar-fine aragonite sand...or even a "mixture" of the two if obtaining enough aragonite is an issue>> I was also thinking of using sand snails to help with the movement of the upper layers of sand within the DSB. <<You can do this (Nassarius and/or Cerith species), though it is not necessary. Sand dwelling/stirring critters will find their way to the DSB in time>> Will they require feeding or will they manage to survive on their own? <<Possibly...best to let the DSB mature for several months before adding>> Any feed back on this would be gratefully appreciated. <<You have mine>> Phil Bowen England <<Regards, Eric Russell...South Carolina>>

DSB/Wet-Dry/Nitrates - 08/28/06 Hi there! <<Hello!>> How are you all today! <<Don't know about the rest, but I'm doing fine, thank you>> I hope I am not bugging you with a repeat question. <<No worries my friend>> I have read thru all your FAQs on sand beds and am getting confused. <<Oh?>> There seems to be many contradictions and I really want to get it right. <<Indeed...differing methodologies/opinions...>> I have a 220 gallon setup that is about 8 months old. I used 220 lbs of live rock to set it up as well as about 120 pounds of CaribSea live sand. That gave about an inch of sand on the bottom. <<Ok>> I also have a wet-dry running and am not sure if this is necessary and will contribute to higher nitrates. <<The wet-dry filter is not necessary, or even desirous, if this is a reef system...but can be beneficial to a FOWLR, though these days my preference when additional bio-filtration is needed is to turn to a fluidized-bed filter>> My nitrates are around 50. <<Mmm, you have a problem then, in my opinion. Nitrates should be <5ppm for a reef and <20ppm for a FOWLR>> I have an ASM G3 protein skimmer and a Blueline 40HDX pump. After the first few months of losing several fish, my tank seems to be settled and I have had luck with my fish for the last 4 months without any casualties. <<Won't last with nitrate readings this high. Though maybe not immediately evident, the high nitrate level will have/is having an effect on the fish and will cause problems/deaths in the long-term>> I'd like to get my nitrates to 0 and am wondering if I should increase the sand bed to at least 4 inches and get rid of the bio-balls. <<One approach>> I could also add some more live rock. <<Sounds like you have a lot of rock in there already>> Would you advise this or should I stick with my 1/2-1 inch sand bed (I lose some sand every week when I vacuum as it's fine sand)? <<I'm a fan of DSBs...I would try increasing the depth of the sand bed...and stop the weekly vacuuming as this will be counterproductive to the DSB. If detritus accumulation is a concern, then increase water flow in the tank>> If I made it a DSB, how would I go about it with all the fish and live rock in there? <<Considering the current depth/weekly vacuuming, simply add the sand until you reach the new desired depth. Pre-rinsing will help to reduce the associated cloudiness>> Can I purchase a different kind and put it on top? <<You can>> I would like to add some pink. <<Won't stay "pink"...I recommend a sugar-fine substrate, though you can go a bit larger if you wish (1mm-2mm)...or even go with a mix of these>> Also, would the LR need to be removed if I was adding 3 or 4 more inches? <<Nope...in fact, I prefer to place my live rock on the tank bottom and fill around it with the sand for better stability>> What about the fish? <<If you go to the trouble to pre-rinse the sand to reduce the "fines" suspended in the water column they should be fine. If you wish, you could even add the sand in stages (a day or two apart)>> I really have no where else for them to go as it's a 220. Maybe knowing my fish would help determine what sand bed is best for my tank. I have a Bluefaced angel, a maroon clown, a purple and sailfin tang, a fairy wrasse, a Twinspot wrasse, a zebra moray and a few gobies. Also 2 anemones and a couple starfish and hermit crabs. <<Yikes! Anemones and 50ppm nitrates? Maybe you should try testing with another brand of test kit (Salifert, Seachem) to validate this reading>> I have had a little trouble with red Cyanobacteria and have been physically suctioning it out every week as well as weekly water changes. I can't get it all off the rock but do blow some of it off with a bulb syringe. I was wondering if increasing the sand bed would help get rid of that as well as hair algae which I have a little of? <<The DSB will provide numerous benefits, one of which will be the reduction of nitrogenous compounds (algae fuels), but an increase in water circulation will also help with the Cyano>> Any help in resolving the sand bed issue once and for all for my setup would be greatly appreciated. <<I think a 4"-6" sugar-fine DSB to be a worthwhile addition. As for the wet-dry, you might try replacing the bio-balls with fist-sized pieces of live rock and see if that helps with your nitrate. Adding some carbon/Poly-Filter somewhere in the filter path will also prove beneficial>> I want to do the best I can for my fish and make it as healthy in there as I can for them. <<Then address/determine the source of nitrate and bring that reading down. Do have a look here and among the links in blue at the top of the page: http://www.wetwebmedia.com/nitratesmar.htm >> You have such an awesome website and I read it often. <<Were pleased you find it of use>> Thanks so much for all your help. Heather <<Happy to assist. Regards, EricR>>

Re: DSB/Wet-Dry/Nitrates - 08/31/06 Thanks Eric for all your great advice so far. <<Is my pleasure>> I did add a Poly-Filter. <<Always beneficial>> I change my carbon monthly and I clean out my filter pad as well as protein skimmer at least every other day. <<Excellent>> I was all set to order 150 pounds or so of sand when I decided first to take your advice and try another nitrate testing kit. <<A good move...and the cheaper route no doubt>> I bought the one the LFS had which was SeaTest and got a reading of 10 or less while the Red Sea by Marine Lab reads at least 50. <<Mmm...>> How can there be such a discrepancy? <<Many reasons my friend...differences in quality/age of reagents, contamination, inaccuracy of the gauge/scale/benchmark...even human error <grin> >> It seems odd that two tests can be so far apart. <<Is advisable to keep fresh test kits of good quality (Hach, LaMotte, Salifert, or Seachem...to name some of the better ones available)>> It makes me angry after spending so much money on my setup and continually trying to find ways to bring my supposedly high nitrates down. Which test should I believe? <<I'm inclined to believe the SeaTest over the Red Sea kit>> I prefer my shallow sand bed and would rather not add 4-inches or more to it if my nitrates are under control. <<Indeed, maybe you don't need the extra denitrification the DSB would offer after all>> I plan on this being mostly fish therefore the bioload will be higher than a reef tank and I worry that in the long run the DSB might not be best for a FOWLR tank. <<The DSB would be fine...though a fluidized-bed filter will react more quickly to fluctuating bioloads and is likely cheaper and easier to install>> I will remove the bioballs and put LR in the wet/dry like you suggested. I appreciate all your help. <<Happy to assist>> I now have a dumb newbie question. <<Ok>> You mentioned that I might want to increase the flow to my tank. <<Yes>> My 220 has two overflow boxes predrilled and I have a Blueline 40HDX pump which I was told was more than sufficient for my tank. <<Mmm, about 1200 gph "before" head loss..."sufficient" for feeding the sump yes, but not likely to provide "sufficient" flow/elimination of dead-spots/suspension of detritus...in my opinion>> However I don't think it pumps your recommended 10-20 times per gallons. <<Likely not even 5x your tank volume, after head loss>> How would I add more flow to this system without it looking ugly? <<Perhaps addition of a couple Tunze Stream pumps, or a "closed-loop" with a multi-nozzle return manifold (see here and the links in blue: http://www.wetwebmedia.com/pbretfaq3.htm and http://www.wetwebmedia.com/circmarart.htm >> I know this is a stupid question and probably very basic but I'm not really sure how to go about increasing the flow. <<Not stupid, and not always "basic", but do read the link/links provided and learn/choose your options. Get some ideas of what you want to do and come back to bounce them off me if you wish>> I do have a deep tank at 30 inches and some Cyano on the sand. It is also only 8 months old and I don't know if this is a phase or something I should address? <<If your only source of water flow is your sump return, increased water circulation may indeed help>> Thanks for all your great advice. <<Always welcome>> I don't trust my LFS very much because when I told them I thought my nitrates were around 50 they said I was crazy to worry as their fish only setups have nitrates of over 300. <<Mmm, well...while it's true that in most FO/FOWLR systems Nitrates "alone" may be no real worry, 300ppm will certainly cause harm. The fact this store claims no ill effect is largely due to the "transient" nature of the livestock ...though their customers are likely not so lucky do to the harm/further insult to health imposed by this store on their livestock with this kind of water quality. In my opinion, it is irresponsible (and probably just plain laziness/ignorance) to subject the livestock to these nitrate levels no matter how long the duration, and even more irresponsible to advise customers that this is "OK">> They seem to think I'm a bit crazy and that I overreact and worry too much about my fish. << (sigh) Maybe it's time to find another LFS...>> That is why and how I found your site and am a true fan. <<Yay!>> Thanks! Heather <<Be chatting, Eric Russell>>

Re: DSB/Wet-Dry/Nitrates - 09/01/06 Hi Eric! <<Hello Heather!>> I think I'm becoming your groupie. <<Hee-hee! Cool, I think you're my first!>> Thanks so much for your speedy reply. I was shocked how fast you wrote back. <<A matter of timing/luck for the most part>> And it's nice to converse with someone who cares about this hobby and doesn't roll their eyes at me when I ask too many questions. <<Mmm, indeed...too bad your LFS doesn't see the value in education/keeping their customers in the hobby...or maybe they just don't have the capacity re>> (Well maybe you are but I can't see it at least like at my LFS) <<Ha! I'll never tell! (and spoil my image <grin>)>> I've been reading and am considering the Tunze Turbelle Stream pump. <<An excellent choice...I use these for water movement in my own system>> It's around $190. <<Not cheap, but excellent quality/engineering/performance>> Is it all inclusive or do I need to buy anything else with it? <<Based on the price I'm guessing you're looking at the model 6080? This is a synchronous-motor pump (does not run on a controller/wavemaker) and is ready to go out of the box. But, depending on your tank design/bracing, you may need one of the holding device extensions (3000.244 or 3000.260). These should be available on the site where you purchase the pump (if not, they can be found at MarineDepot.com), just review the information on each and determine which is needed (if any) for your tank>> The internet stores don't really say much but they talked about timers and wave controllers. Is any of that necessary? <<No...and not possible with some pumps/powerheads>> Where is the best place to put it in the aquarium? <<Hmm...distal from the sump return line...and positioned toward same for creation of a random turbulent flow pattern>> Would one be good since it says it pumps about 2250 gph on top of my 1200 gph I'm already getting? <<If this creates enough water movement to keep detritus in suspension/eliminate dead spots, yes...will likely take a bit of experimentation to determine the optimum position (or number of powerheads required)>> I have a feeling that more gph would definitely help with the Cyano. <<Me too, though other factors to consider as well. Have you read our articles/FAQs on blue-green alga? Here's a good place to start: http://www.wetwebmedia.com/bluegralgae.htm>> I always worried 5X wasn't enough flow but again my LFS disagreed with me. <<You must evaluate the needs/requirements of the livestock, but it is likely an increase in flow will be appreciated...even "enjoyed">> I'm trying to find another LFS but I live in Melbourne Beach Florida and unless I want to drive 90 minutes there are only 2 close by. I'm not too happy with either. <> You were right about the 300 ppm nitrates hurting fish. When I sat down and worked out where all my fish losses were from, they were all from that store. <<Indeed...as if the stresses of capture/transport weren't enough already...>> I think I lost 8 out of 10 of the fish purchased there for a loss of about $500. <<a pity>> All my other fish purchased elsewhere have done fine. <<Hardly a scientific analysis...but does seem rather telling>> I guess they only care about the bottom line. <<Unfortunately there are stores out there with kind of short-sightedness>> Neither store carries live rock and the store that did and had a conscientious owner (shocking), went out of business. <<...why does it always have to be the good one's...?>> Do you recommend any internet sites for quality cured rock? <<Some of the members of my local reef club have been raving lately about the rock offered at Reefermadness.us >> I guess that is it for now. I'd like to purchase a quality pump that gives good gph and add some more LR and see how that goes. <<Sounds fine>> I read the links you sent me as well as Anthony's report on pumps and like the Tunze like you suggested. <<You won't be disappointed>> Thanks so much! Heather <<Cheers my friend, Eric Russell>> Deep sand bed I have read much on the subject of Deep Sand Beds but nothing that puts it all in a nut shell. Is there anywhere I can look that shows the exact complete construction of one of these? I have read miles of varying opinions on this subject, so something solid would be quite refreshing. Actually with as many times you have been asked about this, I am surprised that you have not pointed these people to a complete answer somewhere. <Take a look here http://www.wetwebmedia.com/deepsandbeds.htm, Great article by Anthony Calfo.> 3" 4" 5" (with 5" looking like the target) 6" 7" more? Water in plenum starts to heat up causing slow circulation? What is the normal circulation equal to? (No need for a pump?) <I'm a little confused about what you are asking here, can you please clarify?> What if I wanted to assist this circulation by sucking out some of the water under the plenum with a pump, maybe create a drip or something? My sump is a 55gal glass tank that sits on a cold tile floor on its plastic framing. Will the lower floor temps affect the warming under the plenum creating no circulation? What should the difference in temperature be between the under plenum and room ambient or ambient temperature of the free moving water in the sump? Should I add a heater under the plenum to assist circulation? Would it be to my advantage to create a deeper plenum? (a larger void under the sand. a larger under sand water pocket) I am trying to get a good comprehensive understanding of what's going on so that I can assure the effectiveness of the process. <Definitely take a look at the articles on setups. I think you'll find them very useful> Many Many thanks for all your help. This is the first time I have ever asked a question here. <You've done well! good luck, MacL> Sincerest regard, Paul

DSB & BBT - 05/06/05 Hi Helpful Guru(s), <Greetings> With your help, I have claimed some success with my fish keeping for the past year & you people are the "gold" in our hobby. Thanks!! <Thanks for the kind words.> There has been a debate among my reefer friends on DSB (deep sand bed) vs. BBT (bare bottom tank). The DSB has been blamed as nutrient sink & BBT is the new & better way of doing it, if you are into SPS. With better skimmer technology, there are claims that one should do away with the DSB & just do BBT. <If the DSB is working for you, why would you do this? Doesn't it make more sense to enjoy/reap the benefits of both?> With BBT, you can blow the power heads any way you like & not be afraid of creating a sand storm etc... <Won't argue that...> What is your view on this issue? <I like/prefer the DSB myself. Both can/do work, But it comes down to proper husbandry and proper application of the chosen methodology. I'll grant you that a DSB may become problematic, but ANY methodology will end in disappointment if you don't bother to research and apply it properly.> I understand that DSB helps mainly in Nitrate Reduction. Right? <A primary consideration, yes, but other benefits to be had as well.> Even with a powerful skimmer only without DSB, can one get zero nitrate? <One can get zero nitrate without a skimmer OR a DSB. It becomes a matter of adjusting stocking levels, feeding, water changes, manual detritus removal, etc.> Or, the reason that BBT works in SPS tank since minimum feeding is required & hence minimum NO3 generated? <Faulty logic/information my friend. Feeding and water flow rate above lighting in my opinion (and others here) for success with SPS and indeed all type reef tanks. The idea is to find and correctly apply a methodology where you DON'T have to starve your tank.> I have a DSB tank housing SPS. Thinking of upgrading to bigger tank. How do I move the existing sand in DSB to the new tank so that all my bio filtration is intact & I need not go through the cycle of new tank? <So, you want your cake and eat it too eh? <G>. You must understand, the sand bed is made up of layers of micro- and macro-organisms. The organisms develop and function, indeed survive at differing depths within the sand bed. It's not reasonable in my opinion to expect to move a sand bed without experiencing some mortality of these organisms.> If I move the sand just like that, I am disturbing it & may experience nutrient leach & toxic tank, right? <You may, yes, maybe.... But your biggest hazard is a brief infusion of nutrients to feed nuisance algae, the so called "toxic tank" is more myth than reality. In my experience, any "toxic gas pockets" that are released exit the water column very rapidly, facilitated by good/proper water flow, with virtually no effect on the tank inhabitants.> Does it look like my only viable way is to cycle a new tank with new DSB until it is completely cycled (i.e. 2-3 months minimum); then I can move my live rocks & my SPS over to the new tank? <Not at all. You will have mortalities within the sand bed as stated previously, but not everything will die, thus providing a "kick start" to the cycle process. You will need to monitor water parameters to be sure, but I believe it's reasonable to expect the relocated sand bed to cycle within a couple weeks or less. You might even reduce that time by using a portion of the sand to infuse life in to a new sand bed if you like. Consider the fact that you will be also adding cured/mature live rock to the system.> Gee, now you can understand why I am tempted to go bare bottom tank, no such problem in future; just move live rocks & live stocks. May I have your honest view on this matter. I would appreciate it. <Have tried to do so. Relocating a sand bed is an arduous task. I would recommend seeding a new sand bed with a sizeable portion of the old bed, move your rock and livestock, along with most of the "old" water to the new tank, and go back to enjoying the hobby my friend.> Thanks in advance. <Regards, Eric R.>

DSB vs. Plenum (1/14/2004) Steve (or whichever highly-appreciated crew member is answering today), <me again> Thank you for the response. To follow-up on a few of your questions/comments... <Why put a plenum in your refugium? A simple DSB should work fine.>: I have read many postings on this trying to determine the best approach. GARF.org swears by the use of plenums on all of their "bulletproof" systems. <IMO, no system is fully "bulletproof" either literally or figuratively. Some are surely less likely to fail than others, though. The real key is good maintenance habits.> Even in one of the WetWebMedia postings where someone asked the question "Should I use a DSB or a plenum in my sump/refugium?", the answer was "Why not have the benefits of both? You can include a DSB over a plenum..." <True> I have read having a plenum can be disastrous but it seems that this happens when a plenum is poorly designed/maintained. <Agreed. Anything can be disastrous if mismanaged.> Of course I want to use what is the best NNR method but I have not found agreement on this. <And you will not find it. Put 3 aquarists in a room and you'll get at least 2 differing opinions.> Do you foresee problems with using a plenum or advantages of a DSB rather than a DSB over a plenum? <I think you can do fine with any of these. The key is for you to be willing/able to keep up proper maintenance. You should consider getting Bob & Anthony's "Reef Invertebrates" book and reading the DSB/Refugium/Algae chapters. Very helpful. The rest of the book is great too. You may also want to read some of Bob Goeman's writings on the subject.> <Can you make the refugium any bigger?>: I might be able to make the refugium slightly bigger but it needs to it inside my stand and I would like to maintain *some* room inside the stand to store food, chemicals, etc. I also already have a spare 20 gal high aquarium, so this is just a convenient fit. Are you concerned that a 20 gal refugium will have little beneficial effect on a 180 gal aquarium? <Bigger is always better, but 20G is sure to be valuable. Convenient fit is very important.> Regarding the 100-150 gph flow rate, I should have mentioned that this is the pump's rating. The refugium will be located about 1 - 1 Â½ feet above my sump so the actual flow rate will be reduced. I do want the flow to be low enough to give the refugium time to react with the water so, I will be restricting this flow if it appears to be too high. I had read that a flow rate of 3-10 times the refugium volume is recommended. Do you agree with this? <Yes, but not so much as to disturb the sand bed. I like to be on the lower end myself. 10X flow in a 20G will likely be too turbulent for the sand and the 'pods>

Sump/refugium/deep sand bed - confusion I have been reading many of your FAQs and doing a lot of internet research over the past couple of months. <Research is the best thing anyone can do for a reef tank. Kudos for taking the time to look it all over.> We set up our FOWLR tank 15 months ago and are now wanting to upgrade to a reef tank. Current setup: 77 gal AGA Fluval 404 canister filter Seaclone skimmer 4x96W fluorescent light 2 powerheads approx. 30 lbs live rock 2" live sand/crushed coral bed <Well, the Seaclone skimmers aren't the best on the market, but it does get the job done. If you are going to do light loving corals and things like clams you will need some lights that are much more powerful than that. Check out of the Lighting section on Wetwebmedia.com to learn more about what sort of lighting you will need for the corals you wish to keep. I myself like a bit more live rock in my tank, one to two pounds per gallon. But that is all up to personal taste. If you feel that 30lbs is enough then that sounds fine. As for the sand bed, With larger tanks many reefers are finding Deep Sand Beds to be very beneficial to the overall well being of their tank. I myself use sand beds, and skip the crushed coral. My findings were that large crushed coral has lots of dead spaces for food and waste to rot in. The sugar grain sized sand in my tank not only looks nice it also offers a low oxygen area for the beneficial bacteria to break down the ammonia.> What I would like to do is get rid of the filter and plumb in a sump so that skimmer and heater etc. can be hidden. <Very good plan, tank looks so much more natural without all the extra stuff hanging in the tank.> I understand from your site that the Seaclone skimmer isn't very effective and plan to buy a new one (am thinking about the Aqua C EV180). <A nice skimmer, a friend purchased one recently and he hasn't had any complaints.> First question - is the 4x96 light strip going to be ok to keep low to med light corals (tank is 20" deep)? <Depending on the bulbs you use, and how often you replace them then there are a some low light corals and mushrooms that would do quite well in lighting like that. Other corals you might need to feed more often to balance of the amount of light.> I also plan to add 40-50 lbs additional live rock and create a 4" DSB in the main tank. My purposes for this would be NNR and phosphate reduction. <This is why it pays for me to read the emails prior to answering them. I had addressed the issues above. More rock is good, and DSB are great!> I am currently battling a hair algae problem which I am fairly certain is due to high PO4 due to a lazy maintenance schedule (nitrite is 0 and nitrate less than 10). <Getting a bit lazy with tanks will lead to some outbreaks of some weird stuff. Luckily it was hair algae, which can be eaten by many clean up critters (Turbo snails being a big one). I did a 40% water change 2 weeks ago, and another 25% change last week and plan to continue on a 5-10% weekly water change using RO/DI water. <Good plan.> My test kit only does PH/Ammonia/Nitrite/Nitrate but plan to buy a better kit. <having a better kit will definitely assure that you will know much more about your tanks well being. For corals you will want to know the Calcium and Alkalinity levels.> I am confused as to how to accomplish NNR - so much conflicting advice. <Simply put, by having a deep enough sand bed, which should be around 5 inches, you will have a low oxygen area and should offer a great area for the bacteria to grow and do their work. There are a few good articles in our articles section here on WetWebMedia. And I also suggest checking out the Forums here as well. You will meet a few folks that really know there stuff about NNR.> Does what I am planning sound workable? <To me it sounds quite workable. I've known people have impressive reef tanks with much less.> I don't have much space under the tank and want components hidden as tank is in living room, so would have to pick either a sump or a refugium. I am leaning towards a sump as the refugium would never be seen under there and I would have to find yet another outlet to plug a light into. Basically I need a simple but effective filtration method. I plan to keep my current tank inhabitants (lawnmower blenny, firefish goby, blue damsel, 2 BBT anemones, blue band goby, and canary wrasse) and add some corals like torch coral, mushroom, xenia, easier LPS. <Bubble Tip Anemones are more delicate than any of the other corals you will be adding to this tank. I would do some research into what they need in order to thrive. Anemones really don't have a great track record in people's tanks. In fact somewhere between 80-90% of Anemones imported in die in home aquariums due to poor tank conditions.> Do I need a refugium in addition to a DSB for effective filtration? <Adding a refugium will be beneficial to the tank in general. It's not a needed thing in the grand scheme of things with use with DSBs. But, a refugium will over a larger volume of water, since the depth of the sand bed will remove the effective water volume from the tank.> Thanks for any advice you can offer. Barbara Ottley <Hope that helps. Good luck, and keep up the research. I suggest you also look at getting the book "The conscientious Marine Aquarist" by Robert Fenner. It's a great book and will give you a great deal of knowledge of the subject. -Magnus>

Deep Sand Bed Controversy? Hello! <Hey there! Scott F. here today!> Have to say that I have learned a lot reading all the questions and answers that your group puts out. Thanks!!! I have a 125 AGA tank that I drilled for over flows and for closed loop system, plumbing is ready and now I need to take the next step. <Cool! Now the fun starts!> I have received, through many of different outlets very good advice, and I want to get your input too. I have a 125 AGA (that will be a reef set up) with a 55 AGA sump. I don't want a BB so depth of sand in each? <I'd say 4"-6", if you are shooting for a "true" deep sand bed (DSB)> I Have been told 2.5", have been told 4"+, have been told DSB are accident waiting to happen, been told DSB don't work only when people don't put the right kind of critters in it, etc.... <Imagine that! Contradictory information on the marine aquarium hobby? Nah! Seriously, there is tremendous controversy and confusion on the application of sand beds in aquaria. It seems to me that the people who claim "disasters" after having utilized a DSB in their systems almost always have other issues, such as questionable husbandry habits, excessive bioloads, unusual animal combinations, etc. "Anomalous" crashes of DSB-based systems usually have their origins in some other problem, IMO. The science behind sand beds in aquaria has been well-documented by the likes of authors/aquarists such as Ron Shimek, Bob Goeman's, Larry Jackson, and our own Anthony Calfo. Yes, there is still controversy and disagreement, even among these people! If you don't believe me, just attend a MACNA conference and listen to the heated discussions on this topic! If properly configured, and if the overall system husbandry is up to par, deep sand beds perform remarkably at processing organics and removing nitrate, as well as providing an area for increased biodiversity in the system. A great treatment on deep sand beds can be found in Bob and Anthony's "Reef Invertebrates" book, and on plenum advocate Bob Goeman's website, saltcorner.com. In the end, having a sandbed is a good thing...If you properly follow the "rules" for the methodology that you like. Choose your methodology, care for your tank diligently, and stick with it.> Over flow from tank into sump first passing through filter floss and then over bio balls before entering into sump? I have been told this is to keep the tank from crashing if I have a problem with LR in future, that if I use bio balls I am creating factory for Nitrites, that if I use bio balls they steal the "food" for the LR, if I use floss I steal food for the filter feeds, etc....Please can I have you thoughts on this. <If it were me, I'd omit the bioballs, as they do tend to assimilate ammonia and nitrite so rapidly that they cannot cope with the nitrate that is produced as an "end product" of the nitrification process. If you are shooting for a reef system, or one with low nitrates, bioball-"filtered" systems tend to work against you. If you are using other mechanical media, do be sure to clean and/or replace them frequently, so that they don't become nutrient "traps", working against the other good husbandry habits that you are so diligently developing> Thanks Jim Mc <My pleasure, Jim! Choose your methodology-one that you are comfortable with- and follow the established parameters exactly, and I'm sure that you'll be fine! Regards, Scott F>

Super nutritious DSB/sandbed 5/28/04 Hi WWM friends. Before I undertake emptying my tank and scooping out the sandbed, I wanted to get your advice. <ironic timing... I just pulled 600 lbs from a tank last night that I wanted to move 15 feet into a new fish room. The sand (supplemented over the years) is nine years old and magnificently full of life. It's unfortunate to me that so many people criticizing DSBs haven't actually ever set them up properly (adequate depth, adequate water flow, etc.)> I have a 75-gallon reef tank that is home to four ocellaris clowns, five green Chromis, hippo and Atlantic blue tangs, a mandarin, a goby, a royal Gramma, two cleaner shrimp, a peppermint shrimp and the usual bunch of hermits and snails. <do consider leaving out the hermits... they take a heavy toll on other more desirable life forms in their sand bed> For lighting I have a pair of 10,000k VHO's, a pair of standard fluor. actinics and one, 175-watt halide pendant (5500k). <very nice combo> I have a very large downdraft skimmer in the sump and I use a couple bags of Chemi-Pure and Kent reef carbon in the sump. <Okey-dokey> This is a system that I bought used, minus livestock and live rock, eight months ago from someone who was getting out of the hobby. He had run it very successfully for about a decade. About the only thing living that I bought with the system was the sandbed, which I kept intact because it was full of life. I bought it as a 50-gallon setup and transferred the contents after a few months into my current 75-gallon tank (thus the use of one pendant halide on a 48-inch tank). Four months ago, I was having some trouble with red slime and green hair algae and someone from my area marine aquarium group (Central Illinois Marine Aquarists) told me I should be using R/O water. <hmmm... perhaps. But for other reasons more likely (consistency of evap and source water for new seawater). Not as a solution to a nuisance algae problem necessarily. Do rely on aggressive skimming and strong water flow in large part for this> After I bought a used R/O system, the tank became miraculously clean. The undesirable algae was gone. I was amazed. <this was due, IMO, to the overall attuned attention you paid to the tank at the same time> Well, about a month ago (after three months algae-free), I noticed some red algae and green hair coming back. This red algae was the fibrous kind that harbors air bubbles and lifts off sand and rock surfaces in strands (not the smoother kind that covers surfaces; I can't keep their names straight). <perhaps a dinoflagellate (the strands with bubbles)> I changed the filters on my R/O, but that didn't stop it. <yes... as per above> My phosphate level tests fine and I'm certain that overfeeding isn't a problem. So at the most recent aquarium group meeting, someone suggested that my sandbed is probably harboring a ton of nutrient and is the most likely culprit for the green hair and stringy red algae I'm getting now. <complete bunk... and weak excuse that critics use. At best, it is only true when tanks are run without adequate water flow and nutrient export mechanisms.> This sounds reasonable, and I attached a photo in which I think you can see the red algae growing beneath the surface of the sandbed (sorry the photo is not great). I'm willing to empty the tank and replace all the sand if this is truly the cause, but is there anything else I can do that's not so extreme (and won't smell up the whole house)? <this is truly not necessary my friend... increase your water flow (approach 20X turnover for most reef tanks... close to 30-40X for hardcore SPS tanks> Would something like Bio Chem Zorb or maybe fresh Chemi Pure have any effect? <not likely... too small> Maybe PhosBan (though the phosphate tests OK)? <some merit here... test kits testing for inorganic phosphate only when the majority of phosphate in your tank may be organic> What's weird is how using R/O cleaned up the tank like magic for a few months and now this comes along. <again... not the RO, but your increased attention to the tank at the same time: water change, fresh carbon, improved skimming perhaps?> We also have a 29-gallon FOWLR tank that is nice and clean, so I know the R/O is working. <yes... overall, its a good idea to use purified water of a reliable consistency> You folks have always been a tremendous help. Thanks in advance for any suggestions and sorry this message is book-length. Matt Dietrich <no worries... and please do write back with an update. No kidding... if you increase water flow in the tank and tune your skimmer (clean frequently, adjust as needed) to get it to collect dark coffee colored skimmate near daily, I assure you this algae will be gone in less than three weeks without any other effort. Have faith my friend. Anthony>

Controversial Topics (Sandbed Depth And Caulerpa Use) Hello, <Hi! Scott F. here> I have read through much of the site but still have some questions. First I will tell you what I have--the contents of the tank have been together--Ecosystem aside--for about 1.5 years in a 100 gal tank: My set up is this (for about 6 weeks--I took all the water/sand/rock from the 100gal tank): 60 gal tank 100 lbs. live rock 3-4 inch DSB (fine-medium grain size sand--although more medium than fine) Ecosystem 40 refugium with miracle mud and healthy Chaetomorpha, red tang heaven, and Ulva and lots of pods/snails AquaC Remora HOT 280 watt PC lighting (soon to add another 110 watts) Pacific Tang, Maroon Clownfish in love with his Condylactis anemone, Firefish, Royal Gramma, Rock Blenny, Purple Lobster, two hermits and soon to be removed (although cute) Spotted Puffer as well as one sea anemone. I would like to make my tank non-predator and ready to eventually contain some corals (ergo adieu to the sweet puffer). <And the anemones, too!> I inherited the contents of the tank from a friend and bought the skimmer, and refugium (although the Ecosystem 40 is for a 40 gal I figured it is better to have a small one than none at all at this point--and space is a constraint esp. with a somewhat reluctant spouse who 'doesn't care much for fish' I'm trying to keep it all as inconspicuous as possible). Everyone seems very happy and all the fish responded very well to the addition of the refugium last week (swimming all around the water return...and the normally shy gamma came out and is now all over the tank). No water problems so far. Questions: 1. I currently have the 3-4 inches of sand with the rock resting on top in the tank. The sand is different levels due to the two water pumps I put in--they've blown it around a little (I actually think this looks better than flat sand all the way across). <Me, too!> The manual to the Ecosystem refugium says that I shouldn't have a deep sand bed. My LFS says that that I should have put the rocks on the bottom of the tank, and then filled the tank with sand (three inches) and eventually the sand would settle into the rock. Should I remove some sand? Should I try to put the rocks on the bare tank bottom and add sand like my LFS says? <6 of one, half-dozen of another...I'd keep the sandbed 3-4 inches, and be done with it...> Will the DSB in my tank disrupt the refugium system? I would rather have less sand in my main tank but initially put it all in there since I thought a DSB would be fine (I got it all from my friend with a 100 gal)--also...is it a problem that my DSB sand is not all fine grain but more small-medium grain pieces ( read on your site that fine sand is best for DSB)? <Well, fine grain is best, but it is certainly acceptable (IMO) to have some larger-grade pieces mixed in. Looks better, too! Do read some of the works of Dr. Ronald Shimek on sandbed composition. Lots of opinions on this topic.> I have noticed that after a month the sand layer is whiter on top to the depth of 1.5 inches. Should I simply have one-two inches of sand in the tank since that seems to be the amount of sand that is getting good circulation??? <A lot of the conventional wisdom on sand beds dictates a deeper layer. Two inches may be too deep to be fully aerobic, but too shallow to foster complete denitrification. Again, there are a lot of opinions on this, and new data is coming in all the time. However, I'd stick with the tried and true for now: A sandbed should be 3 inches or more, or 1/2" or less!> If I need to take out sand and re-do the sand/rock would it behoove me to elevate the rock on a PVC/eggcrate setup for better circulation? <Can't hurt- but it's not 100% necessary. I'd personally try to leave as much surface area open as possible. You could elevate the rock or stack it to accomplish this> I really want to do what is best for the long-term/benefit of the organisms. <Agreed! That should be your goal!> 2. Should I add Caulerpa to the refugium? I have read pros and cons. I want minimal hassle and am worried the 'sexual life of Caulerpa' will be too burdensome. But do the benefits outweigh the bother, or will I be fine with what I have? <I like and use Chaetomorpha, myself. It grows, it's an excellent "substrate" for planktonic/amphipod growth, doesn't go "sexual", can be easily harvested, and it's fun to give away to your friends (Everyone wants this stuff at the Club "Frag Swap"! Let everyone else offer their "Blue Torts"- Everyone wants my "Chaeto!"> Thanks for your help--it is very overwhelming and time consuming trying to learn all of this and I appreciate all the time your crew dedicates towards helping people like myself (so hopefully in turn I can help others!). Saskia <MY pleasure, Saskia! That's what we're all about! Sharing this hobby that we all love so much! Good luck! Regards, Scott F>

Embracing The Right Methodology (Tank Set Up) Okay, I've read through the link you sent me on the deep sand bed, and understand that it is not voodoo, but indeed a viable option. Now, my friend does a DSB and excellent circulation, with no other filtration whatsoever besides periodically running a skimmer, but not 24/7, in a sump. His tank is healthy, and there is NO plumbing. Under his tank is completely empty. (very appealing) It seems to me that a sump and 24/7 skimmer would be a better way to go,?,?,?, at which point I am plumbing down to a sump, thus defeating the "neatness" factor he has achieved. In YOUR PERSONAL OPINION, would you go with his set-up? Or a DSB combined with the sump-24/7 skimmer? Or simply the sump/skimmer without bothering with the DSB? <Nope- I'd run the skimmer 24/7, utilize a sump, and also a DSB!> While I understand that your website is written in a fashion that lets the aquarist make his own decision.......I am asking for your personal opinion. If you were me, which would you do? Thanks so much. Pat <Well, Pat- I'm glad that you understand that any advice that you get from anyone- is essentially an opinion, and it's generally up to you, the individual, to make the ultimate determination. I like skimmers (I think that they're essential!), love sumps, and really think that DSB's can make for an amazingly successful system. Go for all three, and I think that you'll be quite pleased! A skimmer is your primary line of defense against nutrient accumulation, while a sump provides extra water capacity, a place for chemical filtration media, and (if you light it) area for macro algae cultivation. A DSB, if properly set up and maintained (i.e.; left undisturbed), can provide excellent denitrification and additional biodiversity. These three systems all compliment each other, and provide ample opportunities for fostering biodiversity and nutrient export processes. Good luck with your system! Regards, Scott F.>

Doing It The Right Way! (Planning A New System w/DSB) G'day Bob, Scott and the rest of the wondrous wet web wizards of the watery depths! This is Rob here from Down Under. <Hey there, Rob! Glad to hear from you again! Scott F. with you again tonight!> I e-mailed you guys a few weeks back looking for advice on my plans for my FIRST marine tank setup. Scott was kind enough to reply and let me know that I was basically on the right track. He then suggested I go back and do MORE RESEARCH!!!!!!! And perhaps revise my plans. I have. I also have many new questions, queries and doubts! <Oh, man- I sent another fellow hobbyist back to the books! Part of the fun, though! > So, here goes..... I am planning on adopting the following species: 1 DWARF lionfish (max5"), 2 LARGE tomato clowns and 1 bubble tip anemone as a start, I'll take my time with these introducing the lion first, then the clowns and eventually if all goes well the bubble tip. <Glad you're "easing" into the anemone...No need to rush> All are available (reasonably) locally and all are caught with nets by people I know well. <Outstanding!> Current plans are for a 150 gal (570litre) tank 48"L X 36"W X 20"H nice and wide, good surface area (see I do read your articles!) I will also be using an under tank sump of 56gal (215litres) I am really hooked on the idea of natural filtration so this tank will get about 200lb's (90kgs) of live rock. <Terrific! It will be a very stable system!> Skimming will be by a locally made (Aussie, Aussie, Aussie OY, OY, OY) venturi unit running from the sump and powered by a 650 g/h (2500lph) pump. These units are made by a bloke in Western Australia who started building his own DIY setups years ago. They have a brilliant reputation and are much, much cheaper than the units imported from your neck of the woods. < Awesome- DO support your "local talent" whenever possible! A good skimmer is such an important investment- well worth it!> Heating will be from 2 - 300W quality units. Lighting will be by fluoro's, 160W of HO and 80W of Actinic (still some doubts as to whether this is sufficient, especially with the anemone in mind.....Your views?). <May not be enough...Even though your tank is relatively shallow, you might want to add a couple more tubes...You simply cannot have "too much" light for anemones, in most cases...> All fluoros are very well reflected and powered by remote, electronic ballasts and will be housed in a custom made (by me!) hood. <The best kind, IMO!> Circulation will provided mainly from a closed loop running on the inside top of the tank with various injectors placed at strategic locations and depths. This will be powered by the 1050g/h(4000l/h) return pump from the sump. I will have to run some test's to see if this is sufficient, if not extra powerheads will be employed. <Sounds nice. If you intend to keep SPS or other high-current loving corals at some later time, you may want to consider a pump or pumps that can push 10-20 tank volumes an hour through the system...Like lighting- you can rarely have too much circulation> O.K. I hear you thinking, this guy's got it together! <Yep! Very much so!> Well that's what I thought too! Until I walked into my LFS (600kms away!). <I've heard of "walkabouts" before- but 600kms...? You're seriously dedicated! I'll never complain about the 20 minute drives to good LFS in my area!> You see, I had initially intended to use a wet/dry filter in my sump to back up the live rock and skimmer. However on looking closely at the shops fish and invert display tank (120gal) all they had was lots of rock and a protein skimmer! Nothing else! This was a good looking tank with all inhabitants looking bright, cheerful and full of life. I was stunned and intrigued. On talking to the shop crew (Seth and Kath, they make a good team!) they told me that the secret was all in the substrate. Sure enough there it was, 5-6" of good looking fine coral sand with plenty of activity going on. <A deep sand bed certainly serves as an excellent nitrate reducing "filter"...a nice thing to have> Anyway I checked it out on the web and found out all about plenum bed construction, Jaubert's method, anoxic bacteria and 0 nitrate levels. After much research I am planning on this stage of using a deep substrate level (5") in my main tank and constructing a plenum system in the sump. The main reason for not using a plenum in both is that I want to aquascape the main tank to resemble a section of reef I know well from diving and having to minimize the rock's 'footprint' would be difficult. I really need your advise on this! Is the full biological filtration method just a pipe dream and is it beyond a beginner like myself? <No- it isn't! Embracing natural methods is probably the most simple and effective thing you can do as a beginner, or as an advanced hobbyist! Your idea of using a plenum in the sump is certainly workable. I personally prefer "static" ("plenum-less") deep sand beds, as they seem to work as well as plenum-equipped systems (although there is plenty of debate on this topic among hobbyists). If you are going to go the plenum route, it's absolutely vital that you follow the "standardized" recommendations concerning sand bed composition, depth, plenum height, etc. These configurations were arrived at after enormous amounts of testing by researchers like Jaubert, Goemans, Gamble, etc., and are not just random numbers. Most of the people who claim that plenums don't work are the ones who "modify" the parameters of their plenum. You may want to check out Plenum guru Bob Goeman's http://www. saltcorner.com site for a lot of good information on plenums...> I am aiming eventually to 'get into' corals so the idea of continuing the biological filtration cycle with the break down of NO3 to NO2 to NO and eventually to pure N is highly desirable. I await your advice with baited breath oh wise and all knowing denizens of the deep! Sorry this is so long winded, got carried away, as usual, if I mention the word "fish tank" one more time I might find myself without a house keeper, bed warmer and long suffering friend! Thanks for your help guys and gals! Rob <Ahh Rob- I think that you're doing great! It's so cool that you're doing the "modifications" and "tweaking" to your system before the system is actually set up! The time that you take now to research the various concepts will repay you many times over with a successful tank! I think a well constructed sand bed (with or without plenum), protein skimmer, and sump, fortified with aggressive maintenance procedures (water changes, etc.) will greatly enhance your chances of success. Keep in touch, and best of luck to you! Regards, Scott F.>

DSB vs. Aesthetics- Hi Kevin, I hope you're in good spirits. <That I am, thank you!> I am sold on the DSB. I was just curious though about the benefits (if any) on a thin layer of sand. Say 1/2 or less. I have read time and time again Steven Pro's view of either 1/2" or less or 3"-4"(for a 35 gallon aquarium). I can hear him saying that "1"-3" is NO MANS LAND for Denitrification, where it is too thick to be aerobic (contains water with oxygen in it) and too thin to be helpfully anoxic". I sometimes can feel his pain/frustration because he has repeated this so many times in the FAQ's, I am sure he and you other guys are getting sick of repeating it. I made a list of Pro's and Con's of DSB Vs SSB for myself and the only reason that I would even consider a Shallow bed is for Aesthetics only. but it's such a significant factor for me to consider. My tank is only 18" high. Going with a DSB would significantly detract from the swimming room of a FOWLR aquarium. <True, but you need not go deeper than 3.5-4"> Would there be more chores involved with as thin layer than a thick layer i.e. cleaning and stirring sand? <Since you're not worried about disturbing anaerobic areas of the bed, stir away!> or is it really about the same in the end as far as the husbandry of the tank goes? <It's not that much different, but you may need to concentrate on other methods of NNR> I guess that the question I really want to ask is "Is considering a fine sugar sand bottom of 1/2" or less really a waste of time or does it significantly contribute to my tank enough to consider a thin bed?" <Personally, I'll be running DSB's in all future tanks, FOWLR or whatever. A deep live sand bed in an external refugium would serve your denitrification purpose for you, while you could have minimal sand in the tank. Pick up Bob and Anthony's new book Reef Invertebrates. It's one of a few (actually, can't think of any others) that bluntly address the whole sandbed depth thing without coming to a conclusion on what is "best". It's got all the why's and wherefores on any depth.> It is funny, I went to my local Big Al's to look at their CaribSea oolitic sugar size sand and I though I would pick the brain of the manager. I ask his opinion about DSB and how much sand he thought I should put in. guess what he said, "about two inches is all you need". <Ask 50 people, get 49 different answers...> After that I thought to myself, I shouldn't have asked. But I do know what sand to get through that exercise because it was the one sand the he only had one bag left of. <Careful, I can think of plenty of things that are quite popular that you shouldn't be using!> that gave me a pretty good indication that that's the sand experienced hobbyist's are using. Talk to you soon. Cheers. Mike Tol

DSB help 10/30/03 I sent the email below back on 10/6. To date, things have not changed. My pH still wants to stay at around 8.6.... <hmmm... not much to worry about. I recommend ph in the range of 8.3-8.6. You are fine where you are at mate. NSW on tropical reefs is 8.45> I have changed water twice, 100% volume . Buffering will not bring down the pH. <buffering with ALK minerals indeed can only take you higher. No point adding it despite ridiculous marketing claims of a few products> What can I do? <relax... or read a bit more to get a better understanding (comfort) of how pH/ALK works. Do check out some excellent articles on the web by Randy Holmes-Farley> This tank has been stuck here now for almost 2 months. I am considering trashing the DSB. <good heavens... the DSB has little to do with it mate. Even if it did, it has so many great benefits! Please don't make a fine situation bad with a knee-jerk reaction like this> but if I do, go to a 1 inch bed, I'm not sure whether the pH will come down then either. I feed the tank regularly, it has cycled completely, NH2, NO2 and NO3 are at zero, algae growth is minimal.....What to do? Thanks, Frank <relax my friend. Your tank is fine. Perhaps read some of our WWM articles archived like my piece on "understanding Calcium and Alkalinity". Also, see if you can get your hands on a copy of our new book "Reef Invertebrates" which has the most comprehensive (and extensive!) coverage of DSB, live sand, refugiums, etc among many other things in it. Kind regards, Anthony>

Converting to DSB >Howdy Crew, Howdy, Marina here. >I try not bug you guys without first doing my research, but I don't want to blow up a year old marine tank. Here's the situation: 29 G Undergravel with powerheads One powerhead with intake sponge on the tank bottom >>I assume this is for additional water movement, yes? >350 Tetratec HO Eheim canister Prizm (yes, I know, I have to clean it every other day for it to work) HO skimmer 2-3" of mostly coarse to medium aragonite and crushed coral substrate 25lbs of beautifully encrusted Fiji LR. Tank inhabitants are: 3 Damsels 4 hermits 1 banded coral shrimp and a recently growing population of Aiptasia anemones. >>Lovely. >I perform bi-monthly 15% water changes (distilled water and Instant Ocean) and change power filter/carbon/PolyFilter every two weeks, maintenance the Eheim every month, but I still have to add buffer to raise pH above 8.2 every couple days. >>This is because you're using distilled water, which I'm sure has all the buffering capacity of RO/DI water (that is to say *none*). It really should be buffered BEFORE you even mix the salt. >All other, Ammonia/Nitrite/Nitrate/Phosphate read 0. I want convert to DSB for more buffering (I have bought 30lbs) of fine aragonite, but really don't want to capture everyone and pull all the existing substrate and LR out. >>Gotcha, but know that if you continue to use the distilled water without buffering before you mix the salt you'll still likely have pH jumps. >Is there a way to gradually add the fine substrate to the existing substrate and remove the powerheads from the undergravels? >>You wish to remove the undergravel filtration completely, yes? >Should I add or remove some of the external mechanical filtration? Thanks, Randy R. >>Alright, I'm going to assume you wish to convert entirely to a DSB, sans undergravel filtration. You won't need to pull the live rock out, but you'll need to move it so you can remove the undergravel filter plates. This process is going to really stir things up, so I'd be sure to have the canister filter cleaned, ready for a few more quick cleanings with all the detritus that's likely to be stirred up. So, dealing with one side at a time (may be a good idea to allow a week or two in between, just to be safe), remove filter plate, shift present substrate, carefully add wet new sand (rinsed, please!), then shift substrate back over. The more carefully you do this, the better, as you'll disturb your bacterial colonies less. I don't think you'll need to disconnect the canister filter, especially with the lovely Prizm you've got there, but do continue your maintenance schedule with both. Once you've got the deep sand bed in, I assume you know you can't vacuum it as you do an undergravel filter. Know that it can take quite some time for it to become well-established, so the less you can disturb it, the better. Light vacuuming of the CC may be necessary, but not for a while. I hope this has answered your questions, and accept my apologies for the late reply, as the person in whose inbox this was hasn't been able to answer queries lately. Marina

DSB substrate 12/9/03 Hi Bob or Anthony, I love your book! When is the next one out? <kind thanks... and Vol. 2 (Reef Fishes) will be out in 2004. We hope to have it ready for late summer perhaps> Is there anything in this hobby other than water which is not controversial? <good point, although can you please define what you mean by "water" <G>?> I am planning a DSB for a new 75 gal tank. I was planning on spending $$ for 200 lbs of aragonite until I read Dr. Shimek's papers on substrates. His opinion is that only the particle size (fine) matters and not the composition itself. <there is merit to this belief IMO and I myself prefer sugar fine aragonite for most applications too (because most folks want/need nitrate control/support)> I live in SW Fl and have beautiful calcite beach sand which he feels would be just as good. <depends on what your perspective is. For nitrate control you will need more of it if it is more coarse... and subsequently need better water flow and sand stirring (you or creatures in the tank). And even if it is sugar fine, it will not contribute minerals as well (at all, nearly... none) as aragonite. Aragonite is much better in this category as it dissolves at a pH of still over 8.0... but calcite does not dissolve until the pH dips into the dangerous mid 7's on the pH scale> He also states that aragonite will not be much of a buffering agent as it does not breakdown until the pH is much lower then it should be. What are your thoughts on this? <I disagree on the latter. From what I've read in science and hobby literature, aragonite dissolves easily in still higher pH waters (over 8.0) and my practical experience with 48,000 lbs of this sand delivered for my coral farm and used over a decade supports this <G>. Seriously... the half life of sugar fine aragonite is a mere 18-24 months in most aquaria... meaning that your 6" bed will be about 3" deep after 2 years and have contributed so many useful minerals in the process> Will I have the same results using the local sand assuming all other things are equal? <good results but not the same. No worries, the mineral loss can be reckoned by more water changes and careful supplementation of your system with calcite instead> Thank you for you respected opinions. <thank you for caring to know them my friend... best of luck. Anthony>

DSB substrate II 12/9/03 Anthony, Wow, talk about a fast reply! You and the Crew are great! <we aim to please... that and we have no social lives and sit by the computer all day. Oh, yeah... we write for a living. Phew... we are not total losers <G>> The buffering question and at what pH is dissolves seems to be the major difference. But we all know it does dissolve, so those minerals must go somewhere! <exactly... and many folks (myself included) have noticed that the need to supplement with Calcium and/or buffer is markedly decreased in such systems> I lean more toward your explanation as you certainly have used enough of it. I suppose in the overall scheme of things, the price of the aragonite is one of the least. <yes... true. And it yields so many natural benefits> I shall plunk down the $$ and buy some! <have you heard about buying this same material from Home Depot Stores packaged as play sand (formerly South Down brand)?> (you don't have stock in the sand mine do you? :)) <heehee...nope. Its a rule around here.... we take no free samples and as such can remain unbiased about recommendations/critiques> Thanks again <best regards, Anthony>

Building Up a New Deep Sand Bed Hi guys hope you are well mailing you from South Africa.. Feeling somewhat depressed after our knock out of the cricket world cup (That's if it even exists in the States) Quick Q I currently have a 100g Reef tank with +- 2inches of medium to large crushed coral that has been my sand bed for over a year and is full of nice little critters. I'm purchasing a 125 G tank and am planning on using your deep sand bed method. Should I put my existing sand at the bottom and then my 3 inches of fine sand on top or vice versa and will this size still be ok to use ? <Well, the "deep sand bed" concept seems to favor a uniform bed of aragonite in the "sugar fine" sand grain size. The uniformity is supposed to foster proper dissolution of nutrient within the sand bed. If I were doing what you're doing, I'd probably distribute some of the existing sandbed material into the new sand bed, to help "kick start" it. The majority of the sand bed should be the fine grained variety to take advantage of the beneficial processes a sandbed is capable. Obviously, you don't want to waste the beneficial life forms that are in your current sand bed, so just try to utilize what you can> Also my local pet shop has told me of fine sand that is very rich in Calcium and gives off Ca for about 5 years. What is your experience with this and do I still need to add Kalk? <Well, this sounds like they are describing the Aragonitic sands that are available, like CaribSea's "Aragamax" products. It's true-one of the benefits of a deep sand bed of fine aragonite is that it will provide some dissolution of calcium and other minerals over time. However, I would not consider a deep sand bed a substitute for other methods of calcium supplementation, such as Kalkwasser and/or a calcium reactor> Thanks guys. Werner Schoeman <Any time, Werner! Have fun building up that new sand bed...Regards, Scott F>

Goin' Deep (DSB Questions) Wow Scott, asking that substrate question just opened a larger can of worms. <Rinse them thoroughly before feeding them to your fish...LOL> I've been reading over the FAQs re: sand beds all morning and am thoroughly confused. <Welcome to my world, man!> First let me tell you more about my setup if I may. I have a 125g tank with an Ocean Clear Canister filter supplied by a Blueline 1100 gph pump. I didn't know any better at the time and followed the advice of the LFS to have the tank drilled through the bottom for the intakes and returns (two of each). <Doesn't sound too bad to me...Can be modified (?) to work with a sump, maybe? Lot's of potential here...> This is what's making the planning of live rock so difficult. Trying to figure out how to arrange it and not block the returns. Both returns are aimed at the surface for surface agitation. I have also installed two air stones in the back corners for more water movement. I have a Remora Pro skimmer that produces a couple of cups of dark stinky stuff every couple of days. <Excellent- dark, stinky skimmate is a thing of beauty!> I also have an Emperor 400 that I keep carbon and Polyfilter in.. <Polyfilter rocks! Best sure to rotate out the carbon and Poly Filter regularly> I cut the carbon out of the filter pads and rotate in new clean ones (bleached and dried) with water changes. I believe I have at least 10 times water turnover per hour. I have 120 pounds of crushed coral substrate that is probably close to 2 inches in depth. I think I finally figured out why I had such persistent algae. < Me, too! You're on to something here...keep going> Now, I was reading in the DSB FAQs that in FO tanks there can be a lot of detritus accumulation in the sand bed which would fuel algae. <Well, there certainly can be. However, a well managed deep sand bed (with occasional light stirring/siphoning of only the top 1/2" of sand can avoid any potential problems...You don't want to disturb a DSB> What would be my best bet? Bleach and reduce the amount of my existing crushed coral, or go with sand. If I go with sand, since it is fish only, should it be around 1/2 inch deep or go ahead with the 4 inches? <Well, either would work. I have kept many tanks successfully both ways. Take also into account the kinds of fishes that you are keeping. If you are a Goatfish or Dragon Wrasse fan, or keep other fishes which dig deeply into the sand bed, this may not be such a good idea. I kind of like the DSB look, some people don't like the aesthetics of the "ant farm" effect that a DSB can show. Frankly, I would go with the DSB. When used in conjunction with regular water changes, filter media replacement (really important in a system designed around largely mechanical filter systems), and overall good husbandry techniques, you should be fine. Sorry to keep bothering you on this holiday weekend. <Believe me, man- not a problem! Your talking to a guy who gets excited about making twice weekly water changes and cleaning his skimmer regularly...Glad to be of service!> Thanks again for all of you help. Vince <Any time, Vince! Have fun, whichever route you choose! Regards, Scott F>

Depth of DSB 7/7/03 First, Anthony and Bob; I'm enjoying your new book. A lot of very interesting reading. Anthony, thanks for the inscription. <very welcome my friend... thank you :)> In it you bring up that 3 inches of sugar size sand is the min. for NNR. Do you have any studies that back that up? Want to know for when I am talking to people about their tanks. <Dr Rob Toonen has released some prelim data on such matters... will have full report soon I hear. Other data exists (some of the original work) from French academic aquarists in France dating back to the late 1980's/early 1990's (Jaubert, Ounais). To be honest though... I'm really speaking from a decade of practical experience. I used 48,000 lbs of the sugar fine aragonite sand for my mariculture facility. Heehee... this combined with similar reports from colleagues led me/us to the statements> The other question is about the "half-life" of 18 to 24 months you bring up on page 36. I've not seen that in any of my tanks with aragonite DSBs. <indeed... 'tis because of the commonly variable pH that works in the favor of aquarists in this case (not dissolving the sand consistently/fast enough... but at the expense of dissolved bio-minerals)> I have a number of tanks with 3 or more inches of aragonite that are 2 to 3 years old and do not seem to show that in any of them. <without a Ca reactor, such tanks usually do not have fast coral growth either (scleractinians). No worries at any rate> Could this be caused by having too many borrowing detritivores or animals like pistol shrimp? Thanks, Ray Pollett <no my friend... really just a matter of adequate water flow and various faculties to dissolve the material. A matter of grain size too if larger. Kind regards, Anthony>

Re: Deep sand bed Dear Anthony, Thanks for your advice again. I just came across articles about the combination of tribased pelletized carbon and "right now" bacteria as a fast means for denitrification. What's experience or views about this? <the industry has seen many such products with miracle claims for more than 20 years... <<Longer than this... RMF>> one hasn't panned out yet. The very nature of denitrification in an anoxic environment cannot be bottled, liquefied or pelletized. I'd be very surprised if they work if this is their claim. Quite frankly... DSB is so simple, effective and proven (not to mention inexpensive!) I have no desire to pursue another method currently. DSB is my strong advice for denitrification> Regards TFChow <best regards, Anthony>

Clumping sand Anthony, Ughh. C'mon, buddy, yer killin' me. I set this tank up in January, so I honestly do not remember (with 100% certainty) which brand I used, but all of the local LFS's carry CaribSea, and I purchased my substrate locally -- and yes, it is medium grade. <indeed... this is a common complaint> Also, my substrate depth is less than 3", <heehee... that's what I get paid the big bucks for <G>. Not a surprise here either> but I CANNOT stand the "ant farm look" of reef tanks with 4" - 5" substrate depths. I'm sorry, but I find it *very* ugly. <Your aesthetic preference is valid. If you do not like the look of a DSB then you simply need to find some other way to manage nitrates. No biggie. Which do you hate more... DSB or weekly water changes (or more)... perhaps less fish... whatever it takes. Its your tank. However, 1-3" sand is not an option IMO. It takes way too much effort to keep from clumping or becoming a nutrient sink. 1-3" sand is not deep enough for denitrification, yet too deep for aerobic faculties. It just sucks in the long run (2+ years). Especially with medium or course grains: Traps a lot of detritus, requires massive water flow in the tank and weekly siphoning of the gravel, so to speak. To other people though, this is of little trouble. Personal preference.> I used 60 lbs. of aragonite in my 75 gallon tank, about 1.5 - 2 inches deep overall. <Ughhh> Why is depth of substrate a possible mitigating factor for this particular problem? <penetration (course grains and not too deep) of spiked water in a low pH environment where fusing can occur more easily (calcite has to hit 7.6 or lower to begin dissolving but aragonite can do so at 8.3!> Would adding 20 lbs. of a another brand or type (fine Fiji pink, for example) help me any? <nope... the grains will settle... might make it worse (no ideal medium for a given faculty to exploit to the fullest> The number of seemingly innocuous pitfalls that this hobby possesses is truly amazing. <very well stated my friend> Anyway, one of your statements: "You were dosing slow enough, but perhaps the concentration in the slurry was too rich. It is a simple matter of too much or too fast." was encouraging. I will work on 'tweaking' my dosing speed and/or concentration. In the mean time, any thoughts on how to address the substrate *quality* issue would be greatly appreciated; but I won't increase the depth substantially. <no worries... if you can otherwise control nitrate accumulation, I'd recommend siphoning sand out periodically until you get to no more than 1/2" depth. At this point with good water flow in the tank you will not have to service it much anymore> I apologize for being stubborn on this one point, but I really think that the "ant farm look" is quite unattractive. < no worries at all. We all have our preferences. You might consider an inline bucket full of sand downstream and out of sight for DSB nitrate control if necessary> I am, as always, very grateful for your time and consideration. <our great pleasure> Your fellow hobbyist (with concrete slab substrate), Mark Schwartz <with kind regards, Anthony>

Nitrates reduced by Deep Sand Beds (DSB) - 2/11/03 Wow! I didn't expect it to work that quick! <yep... literally 2 weeks for most proper deep sand beds (4" or more)> My nitrates were 80ppm for months no matter what I did (FO tank) and I converted from CC to DSB last week, and they're already down to 20ppm... how very cool! <good to hear, my friend!> Thanks for the great website and advice! <our pleasure> Now I just have to remember to keep it stirred! (Not shaken heh heh) <or seek active detritivores> David <best regards, Anthony>

Fact, Fiction, And Nutrient Export... I am in the process of setting up a new tank. A 135 gallon Floribbean biotype. <That should be cool! I'm envisioning the "eye candy" in this reef already! Scott F. with you here today!> Not necessarily a full blown reef in the true sense but their will be a fair amount of gorgonians as well as whatever life comes on the gulf rock. Is 90 lbs. enough rock for bio filtration or do I need more? Now to my main questions. Their seems to be a lot of contrasting opinions and conflicts as I reed through your FAQ's. <Well, much like in the hobby at large- everyone at WWM has their own interpretation of many aspects of reef husbandry...You have to take any and all advice with "a grain of salt", and draw your own conclusion in the end...> 1) Sand bed: Bob Smith said he prefers a 1/2" shallow sand bed. Yet others swear by 4-5 inch bed with a plenum. I would rather save the time and expense and use a 1" bed. But would this provide significant denitrification as well as enough depth for some of the Caribbean wrasses I intend to keep? <Actually, there really is little disagreement and a lot of fact on this topic. The rule of thumb with sand is 1/2" or less, or 3" or more. One half-inch of sand is not enough to provide denitrification; neither is anything less than three inches. Sand beds between 1/2 inch and less than three inches are more or less a biological "no man's land", not deep enough to reduce nitrate, but too deep to be aerobic. This will result in the formation of the dreaded "nutrient sink", which has the potential to create long-term nutrient accumulation and the resulting nuisance algae blooms that accompany it. My advice- Go with a 4-6 inch bed> 2) Sump: Do your prefer an "in line" Ecosystem type setup, or leaving a standard sump in place and using the refugium in a separate closed loop? <Actually, in my opinion, a refugium should be supplied with raw water from the aquarium or sump, so you certainly could have a dedicated pump just for the refugium...many ways to accomplish the same thing...> 3) Size: Bob Fenner has made reference to the largest sump possible. Yet when I look around many configs. Most only have a mud area the equivalent of 10-15 gallons. What gives? <There are so many variables here... I'm not going to try to interpret what Bob meant (well- yeah, I am!), but he correctly points out that a larger sump gives you many benefits, among them the ability to create larger "mud" chambers (if you're into the "mud" thing), provide room for protein skimmers, mechanical/chemical media, and simply add to the overall system volume...Think about it: A 100 gallon tank with a 30 gallon sump is essentially a 130 gallon system (well- almost, because you wouldn't run a sump "filled to the brim" at all times..), so you get the picture here...As Anthony likes to say- "Dilution is the solution to pollution...More water is a good thing!> 4) Plants: I recently read a published article stating that mangrove filtration is not as effective as first thought. <Mangroves really grow to slow to be considered an effective, rapid means of nutrient export in closed systems. they offer other advantages, such as their leaves contributing to beneficial microorganism growth and their roots offering shelter and spawning areas for a variety of different animals. A cool addition to a display, but I would not view them as a viable nutrient export system> On the other hand their is now information that Caulerpa produces chemicals that can be harmful to corals. <Very true...Caulerpa does produce a number of substances which can create problems for corals in closed systems, has a propensity to "go sexual" (releasing it's reproductive products into the water column, degrading water quality), and is just plain "aggressive", often overtaking and smothering more desirable animals with it's rapid growth. That's why my personal favorites are more "purposeful" macroalgae, such as Chaetomorpha and Gracilaria. They are more "stable", grow rapidly, are not overly invasive, and are easy to harvest. All in all, they are much better macro algae for nutrient export purposes> As you can see about the only thing I can find clarity on is a flow rate of 3 - 5x mud sump area. <Well, like I said before- everyone has an opinion...What works for me may seem absurd for you...But you need to be able to sort through "facts" and "opinions"...never an easy process, but all part of the fun of this awesome hobby of ours!> I am hoping you guys can help make sense of this as you always seem to do. Forever grateful, Ken <Hey Ken- I'm glad that you turned to us...Feel free to contact us again any time! Can't wait to see how your system turns out! Regards, Scott F>

Triggers and Sand Beds? All of your responses have been extremely helpful to me so far. Keep up the good work. <Glad to help!> A few more questions. <Sure...> Question 1 Is there a Trigger species that I could house in this 90 gallon for the long term? <Honestly-none. Sure, it can be done, but I think it's not such a good idea> If none, then what species or type of trigger would work in this tank if bought small (1.5 inches) and then eventually put in a larger system (180 gallons)? <Many of the triggers available would be fine, with the exception of the truly larger (like the Niger and "Titan" triggers, etc) species...The more "reasonably sized ones" (max of 9-10 inches) could stay in this setup for a couple of years, if you start them as juveniles, IMO...but they do grow fast!> And, how many years could he live in the 90? <Maximum of one or two years, depending on the other inhabitants, feeding, etc> Question 2 All of that crushed coral gravel (aragonite based) that I have in my tank was bought under the assumption that it would be the best choice for a tank with a trigger in it. Can a DSB work with this messy eater? <Well, not with the "detritivorous species, such as the Odonus, Balistes, Balistoides, and Rhinecanthus species. Definitely more possible with the Xanthichthys species, like the Crosshatch Trigger, Blue Chin, and Sargassum Triggers. These are much more "reef compatible", and usually are planktivorous in nature; less likely to dig up a sand bed...Let's face it, though- a trigger is a trigger...anything can happen...Hope for the best, be prepared for the worst...> I was under the assumption that it wouldn't because the trigger would eat all of the necessary critters that live in the sand. <Entirely likely with most of the more commonly available species> Also, how do you vacuum the sand to get rid of detritus? (The detritus that would presumably accumulate because the critters that eat it would themselves be eaten by the trigger) <With a true DSB, you really want to avoid disturbing the bed as much as possible. If it makes you feel better, you can siphon maybe the top 1/2 inch or so...> I have spent much time perusing your site, and although I have learned much, I still cannot arm myself with enough info to make a good decision here. A detailed explanation here would be much appreciated. Thank-you. <Well- once again, the concept of a deep sand bed and a trigger together is essentially a roll of the dice! It certainly can work with some species, but it can also backfire miserably...Unfortunately- it's your call on this one!> Question 3 If I do keep the crushed coral, is 4 - 5 inches a good amount? Or should I just have 1 inch? <I personally would use an extremely shallow layer (like 1/2 inch or less with this stuff...Unlike the finer aragonite substrates, this stuff can become a serious nutrient trap over time, especially if kept at a 3-5 inch depth...Yes- it can, and has been done by many people...but I wouldn't do it. Why not just a sprinkling of fine sand, like CaribSea's "Aragamax Sugar-Sized" oolithic sand? It looks nice and can be easy to keep clean in a 1/2" depth.> Question 4 I have heard that if you have less then 4 square feet of space for a DSB it is worthless. You might recall my other questions about a refugium, 36 inches deep, 13 inch by 20 inch footprint. Would an 8 inch DSB be worthwhile in this refugium? <Honestly, I have not heard that argument before. If you're talking about a 5000 gallon tank, then I'd agree that 4 square feet of DSB would have minimal impact. However, with a deep sand bed, the much more important issue is the depth...$ inches or more, with a maximum of around 10 inches (frankly, I'd quit at 8" myself. These depths can most readily foster the necessary beneficial processes occurring in the DSB> Question 5 I know you have answered questions on this previously, but tell my please if I have this correct. Above mentioned refugium with 8 inch DSB (not live sand) 50 lbs of LR suspended above the sand by PVC and egg crate (will eventually make the sand live). Will this cause any problems if I do not buy critters to stir or slowly move the sand? Do I have to do any maintenance in this set-up or is it a set-up and forget about it sort of procedure? Can this refugium stay running like this maintenance free for years? (I have heard horror stories of DSB causing noxious chemical releases in aquariums) <Well, in my opinion, I would not call a DSB or refugium completely "maintenance free", but I suppose that minimal attention is acceptable. There are, of course, lots of differences of opinion on this... As far as sand-stirring creatures are concerned, many of the more commonly used creatures actually tend to decimate the very processes we work so hard to achieve...Perhaps a few snails and maybe, maybe, a small brittle star...but that is fine, in my opinion. Unless the aragonite absolutely turns into a "brick" over time, I don't see the danger of not stirring it...again- perhaps just stirring the top layer would be fine. And, yes-inert materials will become "live" after a brief period of time. You may want to check out sand bed expert Bob Goemans' great site, saltcorner.com, for more information on sand beds (although Bob favors the plenum approach, a number of the dynamics are similar in a "non-plenum" equipped sand bed...> Thanks again for all of your advice. <Any time! Hope I was helpful! Regards, Scott F>

DSB in main tank Hi Bob! Why do you recommend placing the DSB in a sump vs. in the Display tank? <Yes... either> I've searched your site to no avail for the answer (the DSB Article is a blank page, and it's not addressed in the FAQ's). <Needs to be written, added, thanks. <Is now> Read these files on refugiums: http://www.wetwebmedia.com/refugium.htm and beyond> I am (slowly) setting up a 92 corner tank-the sump will be a 20 gal.15"dia. x 24"h Hex (or, if I could house an in-sump skimmer, maybe two, one for a refugium w/ DSB & macroalgae and one for equipment ---those are all that will fit under cabinet). Do you feel it would be worth it to include a DSB with such a small footprint? <Mmm, yes... and perhaps a good hang on skimmer would do here... My selection input on WWM.> Thank You! Erik Nelson P.S. Saw a "Yellowtailed Moray" the other day @ the LFS. It gave me the "eye". Any opinions on this species? I know you recommend the non-piscivore(?) eels, but I really would like to keep cleaner shrimp alongside one. <Mmm, maybe take a look through our coverage on muraenids: http://www.wetwebmedia.com/morays.htm and fishbase.org Don't know this common name.> P.P.S. My wife says that eels "turn her on". WOW! <Wow indeed! Be chatting, Bob Fenner>

Retrofit of a DSB and Protein Skimming Hello there... it's been a while since my last question, and once again, I would like to thank you in advance for taking the time. <You are welcome.> My nitrates are at around 100, which isn't too bad because it's a FOWLR, but nonetheless, I want them controlled for the happiness of my fish. <Good, it would be better for their overall health to have the nitrates lower.> My 100G tank has a 40G Rubbermaid sump that holds a TF1000 protein skimmer. The main tank has about 90lbs of LR and only a 1" layer of fine LS. My family of fish include: Naso lituratus - Naso Tang - 5.5" Rhinecanthus aculeatus - Picasso Trigger - 3.5" Balistoides conspicillum - Clown Trigger - 3.5" Premnas biaculeatus - Maroon Clown - 1.5" Diodon holocanthus Linnaeus - Porcupine Puffer - 3.5" Here are my questions: 1) Can I simply add in more LS to turn my floor into a DSB? I was thinking about 3". I'm thinking of moving all the LR to one side of the tank, and adding the 3" of sand to one side of the tank, then moving the LR over on top of the new 3" DSB and repeating the process on the other side of the tank. Then I'd also eventually like to add in another 50lbs. of LR. 2) Do you recommend (I forget the brand name) that sand that comes in the sealed packaging "wet" and "live" or should I just get some fine aragonite and wait for it to become live? 3) I've never quite understood this... does a protein skimmer actually lower nitrates or does it just remove the dissolved organic compounds that eventually become nitrate (basically slowing the production of new nitrate)? <The second answer, removes dissolved organics.> Thanks again!!! - Eugene <You are welcome. -Steven Pro>

DSB Debate Mr. Fenner, Mr. Moe, Mr. Farley and Mr. Shimek <Anthony Calfo, author of the Book of Coral Propagation, in your service while our friend Bob Fenner travels> I was hoping that you gentlemen could clarify what I believe to be misinformation regarding DSBs as the filter that made all other filtration obsolete. <a great methodology, but not so absolute as it has been misinterpreted> I have been involved with SW aquariums for about four years now and wanted to get your opinion on Deep Sand Beds. <my pleasure on a topic that I am also interested in and espouse conditionally> Basically my question centers around many "experts" on the net claiming that all one needs for *any* marine setup including FOWLR is LR and 6 inches of fine sand. <not accurate or responsible for most aquarium systems with a moderate to heavy bio-load (right or wrong)> They claim skimmers are obsolete and that mechanical filters should not house anything, but rather use them for circulation only. <I personally would be inclined to not run most marine systems at all rather than go without a protein skimmer. I find them to be invaluable for most (some exceptions indeed, but we are assuming advice for the masses here who make mistakes like most of us, overfeed or overstock on occasion, etc)> I have seen numerous posts by "newbies" inquiring how to set up their first system and the resident experts tell them no sump, no skimmer, no canisters. All you need is the LR and a 6 inch DSB. <that is dangerous and irresponsible IMO to say to a newbie that does not have an adequate grasp of critical dynamics in reef aquariology to succeed with such advice/application thereof> I would greatly appreciate your input on this matter. Pros, cons, is it bs, are skimmers obsolete and DSBs the holy grail for FO and FOWLR set ups ? etc.. <I personally prefer a DSB in most of my marine aquaria, but appreciate them for the biological diversity/microfauna that they yield and their support of denitrification predominantly. For nitrification and nutrient export I rely on live rock and protein skimmers largely and recommend it to most aquarists just the same.> This seems to be an off shoot of the article by Mr. Shimek http://www.reefs.org/library/talklog/r_shimek_090698.html which is now being applied to FO or FOWLR setups with absolutely no other equipment. Best Regards, Nick Sahadi Friendswood, TX <Nick, thank you for forwarding this thoughtful and popular question. It sounds like we are in agreement. But the constructive dialogue of contrasting opinions is quite interesting and helpful nonetheless. With kind regards, Anthony Calfo>

DSB OR Expensive Protein Skimmer Hello Bob <Hello Antoine> I have a 280gal FOWLR Tank 60x30x30 with a 11" Vlamingi Tang, 7" Red Coris Wrasse, 6" Twin Spot Wrasse, 5" Pink Tail Trigger, 16" Snowflake EEL, 12" Golden Tail EEL, and a newly acquired 18" Leopard Moray. Now what I'm in the process of doing is removing the Snowflake and Golden Tail EEL to a 75 gal tank. I think that I will trade my Pink Tail Trigger in at the LFS for a miniatus grouper or Formosa wrasse since he is always being harassed by the Vlamingi tang. <Okay> Now since I acquired the Leopard moray I'm putting a strain on my filtration system. Water parameters have moved up Ammonia .1ppm, Nitrite.2ppm and Nitrate up to 60ppm. <Yikes... I would forestall feeding till there was/is no ammonia or nitrite period> Everything was at zero except for the Nitrate being around 35ppm. I'm thinking that this is probably going on because of the undersized skimmer. I ordered and now have in possession another Turboflotor 1000 that I was going to use on my new 75 gal but now I'm wondering if I should send it back and get a Euro-Reef CS8-2 (requires less adjustment correct) for the 280 gal or just add a 20 gal sump DSB with about 6 inches of fine sand which would be a cheaper way to control my water parameters and use the turbo-flotor on the 75 gal. My goal is control denitrification and have to do less maintenance. I thought about a refugium but this would require me to cut the Caulerpa back all the time and worry about it dying on me causing a possible disaster. <Not a huge concern> The original Turboflotor did great until I added the leopard moray and I know as he grows that he will put a greater strain on my system. I just don't know if the DSB will do as just a good of a job as the $400.00 Skimmer. <Not... you would need a couple hundred gallon DSB to "do about the same good"> Another thing is before I only had a half of cup full of dark skimmate in my collection cup per week and now its every three days so I know I'm pushing the skimmer to its limit. I have always done maintenance on the skimmer, weekly water changes, run activated carbon, Chemipure and every so often PolyFilter pads. There is also 200lbs of rock in the tank that I think is enough and still allow the fish to have plenty of room to swim around. <Much to consider. Bob Fenner>

Quick Question about Phosphates and DSBs Bob, Besides nitrates, do DSBs or Plenums also remove phosphates? I've articles with conflicting information. Thanks for the help. Evan J. <Indirectly yes they can. But if phosphates are a concern, you are more likely to precipitate them with Kalkwasser (use gently until the pH reaches 8.6, then they will drop out)>

Marine Fish only & sandbeds Hello to Ye of great aquatic knowledge, <hmmm... so many jokes, so little time> I've been reading quite a few of your web pages and clicking the various links and I've sent a few emails and had some very informative replies. I'd just like to say thanks before anything else because my tank is looking and doing better than ever. As I gather information to prepare for the next, not too distant aquarium project, I have a few points of confusion I was hoping you would clear up. First, I have a couple of sandbed related questions for what will be a 374 gallon or larger Fish only/live rock setup that I didn't see too much of on the various pages because most people who wrote in seem to be more on the reef end than the large fish end of the aquarium world and the fish people didn't ask my questions for me; <agreed> 1. I've read the FAQ page http://www.wetwebmedia.com/dsbfaqs.htm (and the other sand bed question pages) and there seems to be common knowledge about deep sand beds in reef tanks and then there are two segments on a page referring to a fish only & live rock tank where Anthony Calfo says "Truth be told, most reef fishes are too much of a burden for our DSB fauna and that is one of the reasons why a fishless, upstream DSB refugium is so popular " <yep... and this statement does honestly make some assumptions about the typically overfed and or overstocked tanks that are so common. As well, most tanks have no where near enough water flow either. As such, DSB methodologies can be easily corrupted with heavy fish loads (reef or no)> and Steven Pro says " which puts both guys on the same page, <agreed> so I would like to ask what would be the opinion at WetWebMedia.com of the ideal substrate (sand, crushed coral ,possibly live rock across the bottom held up 1/4 inch by supports, none, other) <bare bottomed is the easiest and ugliest. Anything else is fine if kept shallow enough (1/2 inch or less) so that detritus cannot accumulate easily. Strong water flow is always necessary (no dead spots) in any tank, and course media is tougher to keep clean> (mostly) Large Fish only aquarium with a large amount of live rock? From my point of view, sand looks the best and always did, but years ago, the advice I always got was that sand is unhealthy for fish only tanks. <that advice was mistaken. Mismanaged sand beds are bad for fishes, properly managed ones are very beneficial if one takes the time to plan and maintain right> Now, everywhere I go .... fish and sand in the same tank. Healthy combination? <can be yes> 2. How much substrate (if any)? <over 5" if nitrate control is needed... less than 1/2 inch if not> 3. I currently use just enough crushed coral to thinly cover the bottom glass in front of the live rock (bare glass under and behind the rock) and use the large ended siphon tube to pull detritus out of the crushed coral during water changes, <a fine practice/application>but with a tank as large as I want to upgrade to (minimum 374 gal.), I can't imagine vacuuming that much substrate on a regular basis unless I do a section at each water change and if sand is used is it just as frequent a job? <that's what strong water flow (keeping detritus in suspension) and two skimmers are for :) Seriously> I see many huge tanks in public aquariums with sandbeds on the bottom and I don't get the impression they vacuum the sand . <massive water flow again><<Most actually do vacuum... but "after hours". RMF>> What is their routine and if that's not applicable to a home aquarium, <easily applicable.. most people just underestimate random turbulent water flow> what would you advise? <above> 4. I have read about reef tanks with 2 inch sand beds and then a sheet of plastic screen to keep it undisturbed and then another few inches of sand for critter access, which sounded like a possible plan in a Fish Only/Live Rock Tank before I read Anthony and Stephens comments. Am I correct that they are saying the issue is not the sandbed disruption (although that could be a problem with large fish), <yes... could be a problem with digging fish especially> but the fish generated nutrients that would still be a problem even with that much sand on a 120 by 30 inch tank bottom? <exactly... nutrient overload... such should be in skimmer> With a screen divider situation, the sand under the screen is to be left untouched always? <not really the point... needs to be sifted by microfauna... not stagnant> 5. I see these newer products of live dry or damp sand in a bag that allow instant aging and stocking of aquariums. <absolutely ridiculous products> Wouldn't ordinary dry, bagged aquarium sand mixed in buckets with the recommended per tank gallon amounts of saltwater BioZyme or other instant bacteria products have the same basic results? <not even necessary... dry sand inoculated in tank with a handful of live... all is "live" in weeks> Would that be more effective than just adding the bacteria directly to the aquarium? <the bacteria products for the aquarium are not much different than adding flake food to rot... they are barely "alive" if at all... simply a usable source of food for inevitable naturally occurring bacteria in tank> Could home made cement mixture base rock created and cured like the public aquariums do be brought to life (aerobic bacteria anyway) <no thrilled with this idea> in buckets with the instant bacteria products? This is part of my master plan (The home made rock) plus the actual live rock I have in the current tank, plus new live rock. <too heavy... learn fiberglass casting techniques instead... seriously. That's what more big aquariums use> Sorry to bug you with what is probably basic knowledge to most active aquarists, but although I've had aquariums for 30 years (17 fresh water, 13 salt), I haven't stayed on top of the new methods in the last few years and it's time to catch up! Thanks, Rich <enjoy the journey, education.. kindly, Anthony>

Deep Sand Bed/No Sand Bed/Shallow Sand Bed? 7/5/05 In planning a new 90 gallon, quick question or two - Do DSBs really, truly play a significant role in nitrate reduction. <They have been proven to perform this function, if properly implemented and maintained.> Some folks seem to downplay them, at least in part pointing to their hazards (crash, etc.) and as being a detritus trap. <A possibility if poor husbandry techniques are employed. The "nutrient trap" idea is often brought up in hobbyist discussions and message boards. With good maintenance and overall husbandry techniques, the deep sand bed can be an effective ally in natural nitrate reduction for many years.> Would it be a bad idea to set up my 90 with say only a 1 inch sugar-size sandbed (more for aesthetics) so as to facilitate keeping the bottom clean in lieu of some nitrate reduction? <If you are going to use some substrate just for aesthetics, then you'd be better advised to go with 1/2", in my opinion. One inch is too shallow to foster denitrification, but possibly too deep to be fully aerobic. A sort of biological "no-man's land", if you will. In summary, it's better to go really shallow.> I'm guessing you'll always come down on the side of the DSB (but not sure)? <Well, I am truly supportive of both DSBs AND Bare bottom techniques! It really comes down to husbandry. I have maintained both with success, and many other hobbyists have as well. My current reef system is actually bare-bottomed. I elected to go with bare bottom simply because I am employing a tremendous amount of flow, which would send sand all over the place! It was not a choice I made for any other reason, really, but it is working fine. I personally do not like the aesthetic of a bare bottom, but you do get used to it after a while. My tank chemistry and overall water parameters are great. I will probably ultimately use a very shallow (like 1/4" to 1/2") bed of medium grade substrate, just for aesthetics, in my system. I might add that I am a water change fanatic and an enthusiast of good husbandry techniques. There certainly seems to be a lot of backlash against DSBs on some of the hobby message boards of late. Granted, no one technique works for everyone all of the time. However, I am not so sure that I agree with or understand all of the things being said about bare bottom technique (like the idea of "wet skimming", which to me seems like a strange concept...Why not just do regular, old-fashioned water changes, and pull out dark skimmate regularly? I'm sure there is a well-thought-out reason for it, but I just don't quite get it.). Like any methodology employed within the hobby, there are some fine hobbyists on the cutting edge researching and sharing their findings, and their findings do warrant your attention, with the usual caveats about employing a healthy dose of skepticism. I do take some degree of offense with those who say that bare bottom or DSB is THE way to go. In my opinion, a DSB is excellent as well. If detritus is allowed to accumulate, bioload is excessive, and husbandry is not up to par, neither system will be effective. Of course, I am convinced that those hobbyists who are successful with bare bottom tanks could be just as successful with DSB driven systems. Sorry to go out on a soap borax, but I think that it needs to be stated that both concepts can work, IMO.> If I go DSB, would 6 inches of sugar-size be satisfactory to see real benefit? <Six inches should do the trick.> Under the 1 inch sand scenario above, accompanying that plan would be a 20 gallon refugium underneath (perhaps with 6 inches of sand there) and a separate sump of about the same size for a good skimmer such as a Euroreef or AquaC 180. With this setup under the tank, would the 1 inch sand bed in the tank be good? Advisable? Not so smart? <The idea sounds fine, but I would opt for 1/2" or less in the display, myself. Either of the skimmers that you mention would be great, BTW!> Just trying to be thoughtful in my planning. Thanks for your time. <My pleasure! Sorry for the essay, but I think that there is much on the subject that we all have to learn! Do share your findings, regardless of which way you go! Regards, Scott F.> DSB (and nitrates) Question 8/18/05 Good Morning Crew! <Andrew> I've got a question, which might not have a simple answer (What does in this hobby? )..... <Don't know... and am afraid to expand on...> My question lies in the necessary size of a remote DSB in relation to the "primary" tank for Nitrate control. I've read every (And there are a LOT) query regarding DSBs on this board, and the info in the Reef Inverts book by Anthony, and Bob, but I'm still not sure I've gotten what I'm looking for. I'm in the process of moving my tank, and will be setting up a 72G bowfront tank, with a 20G sump, and (roughly) a 4.5G HOB CPR Aquafuge for Pod production/Macroalgae. If I don't go nuts on stocking levels, would a 5-6" DSB in the Sump (Probably 2/3's DSB, partitioned for water inlet from tank, and the Eheim 1260 return pump) and Refuge be able to control my Nitrates at or very close to Zero? <Mmm, will definitely help... only practice can tell how much> If you need any further information regarding additional circulation, filtration, etc, let me know. I just hesitate to add the DSB to the display tank as a 72G primary Aquarium isn't particularly huge, and I'm not very fond of the 5-6" sand bed look, <Me neither...> but if it's necessary, function will prevail over form. I realize a lot has to do with maintenance, stocking levels, etc. but is there an effective "rule-of-thumb" ratio of Nitrate-consuming sump/'fuge size to aquarium size? <Not as far as I'm aware, or concerned... the bigger the better... but no minimum, matching value... Just too many other factors to place in a string of variables in such an equation... foods, feeding, lighting... chemistry... temperature...> (I have this really bad feeling you're going to say there are too many variables to tell) <Heeeee! It may well be time for you to join our Crew, start answering queries...> I'd just prefer to add the DSB from scratch, instead of stressing the heck out of the livestock by adding it later should it not be adequate. <Will be fine... I say, go ahead!> Thanks for your help with the question, and for the amazing amount of help and information you provide! -Andy
<Glad to share. Bob Fenner>

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