Chemiblue... carbon use; molly sys.        1/24/15
Hello, I'm new to having a fresh water tank I'm very confused about what is Good and what is Not... I have been to several pet stores regarding what to use and not. Just to have me spending money I didn't need.
<Quite so. And starting with a 20 gallon tank was a very good move. Smaller tanks usually work out as expensive in the long run.>
My question is I have a 20 gallon tank I purchased 3 Mollie fish as well as a heater, thermometer.
<Mollies are less easy to keep than many people think. Hardy in brackish water, delicate in freshwater. Do read here:
http://www.wetwebmedia.com/fwsubwebindex/mollies.htm
Buying a box of aquarium salt and using a teaspoon or two per gallon can be extremely helpful.>
I asked what size heater do a 20 gallon tank requires. He insisted I buy a 100 watts for it and know I'm seeing moisture around the sides if the tank I feel as though it's too HOT for the fish but the water seems okay. Please
I would just like for someone to be honest and helping me.
<Essentially, you choose the heater depending on two things: size of the tank and how cold the room is. Most aquaria need to be maintained at 25 C/77 F, which will normally be around 5-10 degrees C warmer than the room. The colder the room, the harder the heater has to work, hence the higher the wattage. Similarly, the bigger the tank, the higher the wattage needs
to be. Combine the two and you see the need for heaters of lots of different sizes. Getting a heater slightly too big for your tank is never a problem, it simply switches off most of the time. But getting a heater that's too small is a major problem though as the tank will never heat up properly. So while you have a bit of latitude, it's best to err on the side of getting a heater slightly bigger rather than slightly smaller. At the back of the packaging of the heater, it will state what size tanks the
heater is designed for. As mentioned earlier, if the tank is in a cold room, the heater will have to work harder than normal, so get the heater that's "next size up" in the range for your tank. But normally, what the manufacturer states is reliable. If you visit the Eheim website for example, you can download the manuals for their excellent (and good value) heaters, here:
https://www.eheim.com/resources/product//445/downloads/11/EHEIM_aquarium_heater_25_-_300_manual.pdf
On page 2 they state that for a 20 US gallon tank, their 75 W heater will do the trick.>
I love fish and would like to become better with knowing how to care for them. I had 3 gold fish which died. Asking for some kinda of knowledge regarding this.
Also, it Chemi-Blue safe for a fresh water tank I have 3 Mollie's. Will I have to replace my filter with that I'm confused?
<Chemi-Blue is a brand of carbon. It's perfectly safe in freshwater tanks, but not really necessary. For one thing, it removes medications, so you'd need to remove the carbon any time you treat your fish. It also needs replacing every 2-3 weeks otherwise it's just a waste of space.>
Thank you,
<Welcome. Neale.>

Re: Cycling necessary even with remover?   12/19/13
Thank you for the response. Yep the whole thing was really dramatic. Erm, sorry I'm still a little confused as to how to handle this even after doing my research.
<Cycling with a fish in the aquarium is not difficult but it is dangerous (for the fish). Basically, do daily water changes of 10-20%. Do a bigger water change at the weekend (25-50%). Feed minimally, once every 3 days is fine, and offer the smallest amount (a portion the size of a fish's eye is adequate). If the fish is not interested in the food (and this is often the case if water quality is not good) then remove the food at once. Certainly remove any uneaten food after 5 minutes. Keep track of water quality. I favour the nitrite test kit for this. If nitrite goes above 0.5 mg/l, don't feed, and if it's 1.0 mg/l or more, do a substantial (25-50%) water change.
Do remember that during large water changes keeping the water temperature and chemistry (e.g., salinity) steady is crucial.>
Since I don't have another tank as of now, can I just leave my puffer in its tank and cycle in a pail that can hold about 3 gallons?
<You cannot cycle water. All the bacteria are in the biological filter.
Some are on the gravel. But virtually none are suspended in the water.>
I will just do a fishless cycle, put a little fish food and ammonia in the pail and monitor the ammonia, nitrate and nitrite levels everyday? After the ammonia and nitrite levels are near 0, I will then add the filter sponge, replace the sand and water(less than half, since the tank holds 7
gallons)... Does this sound okay?
<See above.>
Thank you.
<Most welcome, Neale.>

Poly filter to remove fragrance - 11/18/2012
Hello, will poly filters remove fragrance from an aquarium? 
<I suppose it depends upon the fragrance....  and what caused it.>
The source was from fragrant Epsom salt that was accidentally used to treat pop eye in a quarantine tank.
<Ah!  Yikes.  Thank goodness this was in a quarantine system.  Let all who read this take a lesson from your good sense.>
The powder brown seems to be doing alright, I just want to make sure I remove all the fragrance via poly filter and water changes, and re-treat with the proper pure Epsom salt.
<Poly filter won't hurt, that's for sure, but don't rely on it exclusively.
 If your main tank can spare enough water to aid in a VERY large water change for the quarantine tank, this would be the best course of action - along with using the Poly filter, which may aid in removing other undesirable stuff (though I don't know if the fragrance would be removed by it).  I would do as large a water change as possible (100% if you can) and
then filter with new activated carbon (which may well remove fragrance) in addition to the Poly filter (which is a very good product and certainly won't hurt).  Bear in mind that the carbon won't last long, and may be worth changing out a few times, every few to several hours.  With luck, the fragrance isn't toxic and this drastic move is unnecessary - but I'd play it safe, were I you.  Best wishes,  -Sabrina>

Re: Jittery fish...  FW Carbon use f'   12/27/11     1/24/12
 Thank you for the reply.
<... Who? You haven't sent along the prev. corr...>
Sorry I've taken so long to reply back.  I wanted to see if my fish were getting any better before I replied any results back.
<Ok>
They have gotten much better. They're always very active when I'm around and seem happier than before.
But I think I'll get rid of the platies, because they've started to steal food from my angelfish and she usually doesn't get enough to eat.  I've made sure they are going to a good home, though  :)
<Good>
The tank is completely cycled through, now, and I've done some weekly water changes to keep the nitrates below 10 ppm (which is what it's at now)
The nitrites are zero, but I've had a little trouble with the alkalinity. 
As much as I don't like using chemicals, I'll need to use them to raise both the alkalinity and the ph.
<Fine... there are commercial prep.s or DIY mixes. Have you seen Neale's pc. re?: http://www.wetwebmedia.com/FWSubWebIndex/RiftVlySaltMixF.htm
the linked files above>
I did have one question though.   My filter always gets very dirty with both the carbon cartridge and the sponge cartridge, and I think it'd be easier to clean if I just had the sponge filter cartridge in there.  Would that be okay to just stop buying carbon filter cartridges?
<Likely so. Most of the commercial carbon/charcoal sold for freshwater is of limited use anyway>
 They're also fifteen bucks per cartridge, and I don't want to spend so much money a month on something like that.  Also, would it be okay to bleach the sponge cartridge? 
<Yes... best to have two (or more) to rinse, let the newly cleaned one air-dry to remove chlorine>
(It's not really sponge; it's a wiry type of plastic sponge, similar to how steal <steel> wool is made )  It started growing some mold last week and I want to get rid of it right away.
I guess that's the last time I use something like cycling liquid for a new fish tank. A friend of mine was luckier though, since she had the same thing and it actually worked; no problems she knew of.
<Some do, some don't>
I have a new thirty gallon setup, but I'll have to put that on hold for now. I'll try harder to keep up on weekly/biweekly cleaning. It will be easier with the platies gone.
<Ah yes>
Thank you again for the reply.
I know it's a little late, but I hope you've had a happy holiday  :)
-Jenny
<And you, Bob Fenner>

Filter Carbon Question / Honey Gourami 9/15/11
Hi Neale.
<Lorie,>
I wrote you months back about my aquarium and the topic of filter media came up. You seemed to strongly feel that carbon had no place in an aquarium filter. I certainly respect your opinion, so I have changed over to poly fiber inside a media bag and ceramic noodles, and it seems to be working fine. Although I may slowly switch to a sponge, because I'm afraid some of the fibers will get into my propeller. I've done some research though regarding carbon and I haven't found any adverse information about using it in a filter. So if you wouldn't mind explaining; why do you feel carbon should not be used?
<Here's my take on carbon. Firstly, carbon wears out very quickly. To do what it's advertised to do, you need to change it every couple of weeks.
Very few freshwater aquarists do that, so the carbon they use ends up coated with bacteria and/or saturated with organic chemicals. Secondly, carbon removes medications. Countless aquarists have used medicines to treat their fish, and then wondered why their fish still died, even from otherwise easy to cure things like Whitespot. The culprit was the carbon, removing the medication before it had a chance to work. Finally, carbon doesn't really do anything useful in a freshwater tank. Carbon is used to remove organic materials that lower pH and tint the water yellow. That was useful when people did 10% water changes monthly, which was the norm through the 70s and into the early 80s. But since that time people have learned about doing bigger water changes, 25% a week, or even more, provided they can keep water chemistry constant. In doing these big water changes the organic chemicals are diluted anyway, so the carbon doesn't really have anything to do.>
I've also read an article written by you about tropical fish that would be suitable for beginners. A fish listed on there to avoid was the Honey Gourami. I have a ten gallon tank that houses a Honey Gourami and Corydoras. At the pet store, the Honey Gourami just kind of floated around, not doing too much, so I wasn't sure if I wanted one. But after mine became settled in the tank, she is very active and inquisitive. She's really entertaining! I had a spike in Nitrate at one point (over feeding), and she did not seem affected at all. I also have hard water, but she seems quite happy and active. So I'm glad I tried it and it's working out.
<Colisa chuna is an excellent species, but it doesn't always do well in hard water. Soft, acidic water is usually recommended, though I dare say the farmed specimens are a bit less fussy. Compared to the Dwarf Gourami I'd certainly reckon them a better bet, but it isn't a 100% sure-fire species for beginners.>
I was just curious on your thoughts. Thank you, Lorie
<Thanks for writing, Neale.>

Solid Carbon Dosing in Freshwater (RMF, views on marine usage?) <<The same>>   8/15/11
Hello,
I've been reading up on Solid Carbon Dosing in Saltwater Tanks. Is this method feasible in a Freshwater Tank? Providing a suitable reactor of course, would one expect to see any benefit?
Robert
<Hello Robert. In theory it'd work just as well in a freshwater tank as a saltwater one. Both tanks contain the anaerobic bacteria that break down nitrate and phosphate. However, in practise it just won't be worthwhile.
Under strong lighting, higher plants will be removing nitrate and phosphate at rates orders of magnitude above what an aquarium-sized anaerobic filter will achieve. If you think about something like Floating Indian Fern, you can remove armfuls of this stuff from medium-sized tanks every couple of weeks -- and much of that will be protein containing nitrogen and phosphorus! The saltwater side of the hobby lacks such large-scale plant growth outside of specialist applications such as algal scrubbers, and of course saltwater livestock is much more sensitive to nitrate and phosphate than freshwater livestock, so there's a greater pressure to find adequate solutions. The flip side is that freshwater tanks tend to be more heavily
stocked and the livestock fed much more, so the sheer quantity of nitrate and phosphate soon overwhelms most any anaerobic filtration system. So even in a plant-free freshwater tank such as a Rift Valley cichlid set-up, I can't see any obvious benefit on solid carbon dosing. Bob F. may have more information on how/why solid carbon dosing works; I can't pretend to have study this in any depth at all! Hope this helps, Neale.>

Re: Purigen Seachem-a couple of more questions. <<Neale, any comments re: this freshwater query?>> 4/27/10
<Hello Pat. The idea <freshwater> fish absorb nutrients from the water column is likely spurious. There's nothing in any of my ichthyology textbooks to suggest that this is the case. All the lab work and fish farming does seem to demonstrate fish get the nutrients they need via their diet (the exceptions being, for obvious reasons, water and sodium chloride, which depending on whether the fish is a freshwater or saltwater fish will simply be reserved from whatever is processed via osmoregulation). Now, when it comes to lowering nitrate, unless you're very deep of pocket, these chemical methods usually don't work. Fish produce a lot of ammonia, and unlike marine systems, freshwater systems are usually heavily stocked and the fish generously fed. Also unlike saltwater systems, freshwater systems generally lack "live rock" where nitrate reduction can take place. So the average freshwater tank will have lot more nitrate than the average saltwater tank.
Because freshwater fish are largely indifferent to nitrate, it's also less of an issue. Plants will take up nitrate very rapidly given good lighting conditions, so they can help too if you have lots of them; if you're removing armfuls of Indian Fern once a week, you're likely removing substantial amounts of nitrate right there! But the biggest issue here is that freshwater is cheap. There's nothing to pay for in terms of salt, so provided your tap water has the right water chemistry for the fish you're keeping -- as it should -- then simple water changes should keep nitrate under control. Even here in England where city water can have nitrate levels of up to 50 mg/l, that's still well within the tolerances of most community fish. On the other hand, if you have an Arowana, Stingray, or some nitrate-intolerant fish than needs nitrate levels below 20 mg/l, then water changes with tap water might not be enough. In that case collecting rainwater or using an RO filter will be far more cost effective than chemical media that remove nitrate. Much better to have zero nitrate going into the tank than trying to wrangle downwards the nitrate level in the aquarium if it's partly from the tap water and partly from the fish. I cannot stress too strongly how expensive using chemical media this way will be if you're keeping large predatory fish. When all is said and done, cloudy water and algal blooms are rarely if ever to do with nitrate anyway.
They're more likely to do with unstable water quality/chemistry conditions in the tank; overstocking; the lack of fast-growing plants; wrong/inadequate lighting for the plants you have; substrate that hasn't been cleaned properly; and inadequate mechanical filtration. Hope this helps. Cheers, Neale.>
Re: Purigen Seachem-a couple of more questions. <<Neale, any comments re: this freshwater query?>> 4/27/10
Thank you!
Pat
<No problems. cheers, Neale.>

Nitrogen Cycle & Carbon Filter clarification 1/6/2010
Hello WWM crew,
<Hello,>
Sorry about the length of this email, but I could really use your guys advice. About a week ago my family and I got a 38US gallon tank, stand, AquaClear Power filter 70, a heater, LFS Brand Water conditioner for Chlorine and Chloramine, LFS Brand Multi-Purpose Bio-Support (Claims to have 300 million live bacteria and helps lower ammonia levels).
<Actually, fairly pointless stuff. A mouthful of spit contains millions of bacteria but doesn't do much for aquarium water quality.>
Quite a nice X-mas present =)
<Indeed!>
As grateful as I was, we didn't get a freshwater test kit and my financial situation was a bit tight so I was unable to get one (For a mini test kit, like API Freshwater Master test kit, they are roughly $50 where I live, test strips are close to $20.)
<I see. If you don't have a test kit, then doing things "by the numbers" becomes very important. Go slow, act conservatively, and work to preempt problems before they happen. In other words, cycle the tank without fish if possible, or using the hardiest fish otherwise, and do daily water changes for the first three weeks (or more) to take the edge off any ammonia and nitrite. 10-20% daily should do the trick, plus 50% in the weekend. No, this won't slow down cycling.>
We followed the instructions provided to us from our LFS. We got the tank setup, poured the substrate, setup the filter and heater, filled the tank then turned on the filter. When I was putting the garbage away, my family opened some trial packages that were included, followed the directions and dumped them into the tank There were three trial packages, one was the water conditioner I mentioned earlier, the other was the bio-support and the last was a "bio-clean" (It claims to reduce the time and need for cleaning power filters, gravel and interior aquarium surfaces, it's an organic waste digester)
<All fairly nonsensical stuff. If it worked, we'd all be using it. At best, it does little harm. So while water conditioner should always be added to an aquarium, almost nothing else in terms of additives is useful. Bacteria sold from fridges might be helpful, but anything sold at room temperature almost certainly won't be.>
and I didn't find out about this until the next day when a relative stopped by to give my kids some Zebra Danios to help cycle our fish tank (8 to be exact). I originally wanted to do a "fishless cycle technique" but my family has a history of keeping fish and using the old method of fish cycling.
<Pros and cons to this approach.>
So for the first couple of days, we kept the fish in the tank and followed the directions we found on various websites including yours (minus the testing of the water) for fish cycling. On the third day, in the evening I noticed one of the Danios was deformed it looked like his spine was bent but he was still swimming around and eating, I also noticed one of the other Danios was at the top of the tank gasping for air. I thought the ammonia/nitrite levels might be too high so I did a 20% water change and used the water conditioner. Unfortunately it wasn't enough and the little guy passed away when I was draining the water out of the tank. The next morning I was able to pick up the API Freshwater Master Test Kit. When I got home, I was looking at the tank and noticed the water level was not level by over 1/2 inch on the left and the "deformed Danio" was gasping for air and laying on the substrate. I grabbed my level and checked the tank and stand. The stand was damaged and the store would not take it back (Big chain LFS said it was an x-mas day final sale), so I had to run out and buy a new stand. When I got home the deformed Danio was tumbling in the water so I took him out and placed him in a cup with tank water. I then emptied the tank and kept roughly 70% of the water, put the 6 Danios in the old tank water, and set up the new tank stand. While using the gravel vacuum I noticed there was A LOT of uneaten food in the gravel!
<Implies inadequate filtration. If stuff is being left in the gravel, then the filter lacks "suck". I can't stress too strongly how manufacturers wildly overstate the efficacy of their filters. Aim for at least 4 times the volume of the tank in turnover per hour. For a 38 gallon tank, you're after 4 x 38 = 152 gallons per hour. Ignore comments that suggest a filter is for tanks up to X gallons in size. Look specifically for the gallons/hour rating.>
During the stand change, the deformed Danio died. After that ordeal I was finally able to test the tank water and my tap water. Here are the results
Tank Water
Nitrate = 0ppm
Nitrite = 0ppm
Ammonia = 0.50ppm
pH = 7.6
Tap Water
Nitrate = 0ppm
Nitrite = 0ppm
Ammonia = 0.50ppm
pH = 7.6
I also found out my city's tap water is using Chloramine
<Treat accordingly. Use a water conditioner that treats ammonia as well, to neutralize the ammonia in tap water. Understand that such water conditioners DO NOT treat the ammonia produced by fish, just the stuff in the tap water. They're a one-shot deal in this respect, and not an ongoing benefit.>
The next morning I tested the tank water again.
Nitrate = 0ppm
Nitrite = 0ppm
Ammonia = 0.75ppm
pH = 7.6
<Right, the ammonia is going up because of the fish. This is normal, and you'll see ammonia rise, peak, and fall within a 2-3 week period. Nitrite will do likewise, but a few days, maybe a week, behind the ammonia peak/fall.>
I have a few questions...
<Fire away.>
1) According to your websites information about the Nitrogen cycle, with the ammonia levels slowly rising is the nitrogen cycle starting? My wife and kids are getting overly anxious about getting Angelfish (that's what we're trying to get the tank ready for).
<It all depends on temperature, water chemistry, and other factors. Filter bacteria prefer hard, basic water around 25 degrees C. If the water is cold or soft, the process will be slower. A filter that doesn't have a good circulation will mature slower too, because less oxygen is getting to the media. There's no timetable, but a tropical tank should be cycled within 6 weeks. Don't even think about adding Angels until the tank is 3+ months old. Angels are acutely sensitive to ammonia and nitrite, and are easily killed.>
2) I've read much conflicting reports about carbon filters. Would you recommend that I get rid of my carbon filter in my AquaClear 70 and replace it with something else? I currently have the default sponge filter, carbon filter and a "Biomax" filter inside it (White rocks in a mesh bag, sorry don't know what it's called at the moment).
<Carbon is largely redundant.
http://www.wetwebmedia.com/FWsubwebindex/fwfiltrmedart.htm
Read up on what carbon does, and you'll probably come to this conclusion yourself.>
3) Will installing a bubble wall be ok in the tank for my current and future inhabitants?
<Depends on the fish. Angels don't like turbulent water flow, but Danios and Corydoras do.>
Sorry about the lengthy email, but your advice and expertise would greatly be appreciated!
Thank you in advance,
Justin
<Hope this helps. Cheers, Neale.>

Re: Neolamprologus splendens breeding ? (Now: cloning filters)  11/13/09
Yes, I understand what you are saying however these Penguin filters are as such where they have two disposable carbon/filter pad slide in baskets and a bio-wheel.
<Ah, these filters can be a pain to clone. But if there are two of these carbon/sponge "modules", then moving one to a new filter of the same type will instantly mature it.>
So I just took the dirty filter out of the already established filter and put it in the brand new filter. Later today I will put the already established filter in this tank as well. So I will be running two of these Penguin 150's in this tank. I see a newly available item for these filters is a re-fillable media basket which I will be ordering today as well as these filters are rather costly and I am into reducing waste and saving some bucks.
<Oh, very definitely! One reason I do not like hang-on-the-back filters is that most of them use these proprietary modules. These lock you into buying new modules every few months. Indeed, carbon needs to be replaced monthly if it's to do any work at all. I'm cheap at heart, so use either box filters or canister filters that I can load with whatever is to hand:
filter floss, gravel, ceramic noodles, etc. I can then shop around for whatever's cheapest.>
Cheers back at 'cha !
Sooz
<Happy to help. Cheers, Neale.>

Re: Neolamprologus splendens breeding ? (Now: cloning filters)  11/13/09
Howdy yet again, Neale,
<Indeed, howdy.><<Heeeee!>>
I had the thought today of taking one of the used carbon / pad cartridges and try to remove the pad, punch some holes along the perimeter and refill the carbon section then use a cheap but heavy thread to lace a pad back on.
<Might work. You can also buy things called "media bags" into which you can stuff whatever you want, and them ram them into filter compartments. The problem is that filters are designed such that water flows through them in a certain way. With a canister filter, the compartment is basically a cylinder, and you can fill it any old how and it'll work. But with (most, not all) hang-on-the-back filters water is channeled through slots so it passes through these modules in a certain way. So whatever you do, take care not to deform the shape of the module too much, or water will (of course) follow the line of least resistance, bypassing the media.>
It would be a bit time consuming but if I can get this to work then I can just rotate these cartridges. Of course the pads would be rinsed in-between services.
<This is my thing with any system that relies on modules. I don't like being locked into buying them or having to come up with schemes that maximise my expenditure.>
I am having visions of carbon going everywhere.
<Yes.>
I run Emperor 400's on my larger tanks and they have re-fillable cartridges. still a pain to get a decent amount of carbon in them, though.
<Why bother? Carbon largely useless in freshwater tanks.>
On another hand, do you think it would be possible to load the cartridge area of the filter with those re-fillable media bags ? Say, sponge on the bottom, then a bag of carbon and on top, a bag of noodles. Would this be overkill with the bio-wheel?
<Anything that maximizes the area for biological filtration is good.>
Sooz
<Cheers, Neale.>

MARINELAND C series filters, FW chem. filtrant use   10/22/08 please tell me about the use of such materials as Purigen and Polyfilter and activated carbon. Do they really help? <Total waste of space in most freshwater community tanks, though at least some chemical media are more useful in marine systems. Much said on WWM about filter media. Read, and make your own mind when the benefits of a certain chemical medium justify reducing the biological and mechanical filtration capacity of your system. Do also remember most chemical media need regular replacement, so there's a cost/benefit factor to consider as well. http://www.wetwebmedia.com/FWSubWebIndex/fwfiltrmedart.htm Cheers, Neale.>

Are the 3D backgrounds realistic. I have only seen pictures of them. 10/21/08 <Depends on the brand, I suppose. They come in different types, from inexpensive, fairly thin (5 mm or so) textured plastic sheets through to deluxe ones that are 5-6 cm in thickness, realistically coloured, and cut to look like rocks and tree roots. The Juwel branded ones cost about £30-35 for a 50x50 cm piece and once in place and siliconed into position look really good. The only catch is that certain catfish (Panaque spp.) destroy them. Other than that, they're excellent and highly recommended.> And as far as the algae, I don't plant on letting it cover the aquarium that bad. <OK. Cheers, Neale.>

Activated carbon & liquid fertilizer  7/19/08 Hi, just want to know if I add a liquid fertilizer to my freshwater aquarium with an activated carbon in my canister filter, will the fertilizer still be effective? Or should I remove the carbon? Thanks <Activated carbon only removes organic molecules (with a few exceptions like iodine). Since plant fertiliser contains inorganic forms of nitrate, phosphate, iron, etc. you should be fine. So go ahead and use them both! Though as I've commented elsewhere on WWM, the use of carbon in freshwater aquaria is generally redundant and arguably a waste of money and filter space. Cheers, Neale.>

Question- Carbon Stunting Fish 06/15/08 A discus breeder I know, who appears quite knowledgeable, told me that activated carbon in filters stunts the growth of fish. Is there any truth to this? < I have never seen any scientific documentation validating this claim. If this breeder set up six tanks of baby discus with activated carbon in their filters and then set up an additional six tanks of baby discus without activated carbon, then raised them together with all the other factors being the same, then we can compare both the tanks to see if the carbon made a difference. Carbon removes organics from the water. A good example would be tannins from driftwood. What does affect fish grow is nitrogenous wastes. If the filter is not cleaned then the organics in the filter begin to decompose and these waste products inhibit the grow of fish. This is why water changes are so heavily stressed in raising baby fish.-Chuck>

Fluval Filter Media, Water Polishing, Carbon/Chemi-Pure 4/13/08 Hello WWM gang, Thank you for your great site, wishing you a happy spring. We have a 125 gallon community tank with 40-45 fish (Corys, swords, mollies, platys). We operate a Fluval 405 and a Fluval 305 and a UG. We change water 2x weekly (25% each time, with a UG vacuum and Fluval clean). Our water is clear, parameters are fine (we do have to watch nitrates). Questions specific to 'filter wool' in the Fluvals and question on use of carbon vs. 'Chemi-Pure' product. <Neither critical to freshwater fishkeeping, so use whichever you want. I personally consider both a waste of time/money compared with good quality biological media and generous water changes. Compared to these two things, any carbon or equivalent product has a tiny, tiny impact on water quality.> After the Fluval first stage sponges, in our lower basket we always use 'filter wool' as a fine mechanical filter and change it weekly. We use charcoal in the next basket up (monthly change) and then two baskets of bio-max ceramic rings (Fluval 405) and one basket of rings (Fluval 305). <So far pretty normal.> Fluval says to place filter wool in the bottom basket, and that makes sense to filter particles so they do not clog the ceramics. <Yes; about the only thing that really matters with a canister filter is that the biological media should never become completely clogged with silt. A bit of silt won't do any harm, but if you see the water flow visibly dropping to less than half its normal rate, you have a potential problem with insufficient O2 getting to the bacteria.> Fluval says to buy their "polishing pads" and place in the upper basket (meaning after the ceramics if this procedure is followed). Are we doing the same "polishing" the water thing by using 1" thick inexpensive filter wool in the bottom basket only? <Pretty much yes. Provided the biological media (the ceramic noodles or sponges) stay relatively clear, then you can use whatever you want as the pre-filter. My filters containing nothing more than generic filter wool for the pre-filter and either the original sponges or good quality ceramic noodles as the mechanical and biological media.> Is the Fluval product (we have not seen it) a finer filter material than the generic filter wool? Do we accomplish the same thing by folding the wool into a thicker bundle? <Better to use a thinner layer you change more often, because too much will reduce the flow of water. But in any case, experimentation and observation will provide all the answers you need.> Does the filter wool need to fill the entire basket, or is one inch in the bottom of the 3" tall basket OK? <A thin layer should be fine.> Do we need to add a Fluval "polishing pad" to the top basket or can we stay with our method? <Your method is fine provided [a] the water quality is good (i.e., zero ammonia/nitrite) and [b] the biological media doesn't clog up too fast.> Carbon/Chemi-Pure: Your site advice in most FAQs says dump carbon and fill with ceramics; but also suggests in other FAQs using Chemi-Pure in place of carbon. <There's a difference of opinion among some of us as to the value of Carbon (and equivalent products). I'm very much anti-carbon in freshwater tanks. For a start, it's benefits are trivially small compared with water changes. So it removes "organics" from the water. Fine. So does a 50% water change each week, at lower cost, and with the added benefit of removing nitrate too. Carbon stops the water going yellow. Great. So do water changes. And so on. The big negatives to carbon are that it is [a] expensive over the long term when used such that it "works" at all, i.e., 100% changes of carbon on a 2-4 week basis; and [b] it removes medications from the water. This latter has resulted in the deaths of goodness knows how many fishes that people treated for Ick or whatever and then were surprised when their fish kept getting sick.> First, should we forget carbon and Chemi-Pure altogether and opt for more ceramics? If the answer is 'maybe', what are the deciding factors? <I would.> If answer is more ceramics, please answer this Q anyway: Chemi-Pure specs say it lasts 4-6 months. Is this true? <Highly doubtful. All these sorts of estimates of chemical media longevity depend upon the context. In an under-populated tank receiving massive, regular water changes then perhaps yes, this sort of estimate can reflect reality. But in the average tank with lots of fish getting lots of food and relatively modest water changes, I'd be highly surprised if the chemical media really worked that well. Chemical media manufacturers rely on the fact that you can't possibly test their products and pull them up on it. How do you know when the media is "full"? What test would you use? They could be selling you dried macaroni and it wouldn't make any difference -- you're getting a product that you can't observe working, can't measure its efficacy, and can't tell if its doing nothing at all! No wonder they love to sell the stuff!> If so, what is this material and how is it different from carbon/charcoal? <In practical terms, very little. Chemi-Pure contains chemicals that (are said to) remove a few inorganic pollutants including phosphate. Given that phosphate isn't a toxic chemical in freshwater tanks receiving regular water changes, this is more a marketing gimmick than anything else. You should always remember that this stuff is mostly just charcoal, and costs virtually nothing to make. The profit margins are terrific, and hence aquarium hardware manufacturers are obviously keen on selling the stuff. Back in the old days when people avoided doing water changes, carbon served a useful role removing tannins and organic acids from the water. Without it, tanks often looked rather yellow. But in this enlightened age, it's redundant, and nothing carbon does isn't better done with a 25-50% water change at the weekend.> Cheers, thanks! Rosemary <Cheers, Neale.>

Cichlid... spot/markings... and FW carbon use  -- 03/20/08 Hello, Neale <He's on holiday> I have 55 US gallon FW tank with 5 fishes in it: 2 parrots (hybrid), 2 Severums and 1 Sailfin leopard Pleco. I have two questions about my tank. 1) One of my Severums had been in the tank for about 7-8 months. When I bought him he was about 2 inches long. After few days I noticed that he has 3 white spots on his body and occasionally scratches himself. I thought it is ich <Mmm, no... not w/ just three spots, and not just on the one fish> and treated the tank with the salt and high temperature for 2 weeks. He stopped scratching but those spots never go away. Now this fish about 4 inches long, acting normal, but I can see same white spots that probably even bigger. Do you have any idea what is that? <Possibly an embedded worm complaint, maybe a Microsporidean... there are a few possibilities here... None really treatable, nor tremendously debilitating> It still looks like ich to me, but definitely it is not. 2) I followed your advice on WWM and stopped using carbon in my filter. After that I noticed that pH of my water drops from 8.0 to 7.6/week between 50% water changes. I don't think it is overfeeding because my nitrates change only from 10 to 20ppm. Do you think I should use carbon again? <I would. Not all our opinions on WWM are identical... but for the reasons/observations you make, I am a fan of periodic carbon use.> Thank you for your help, Mark <Cheers! Bob Fenner>

Mystery Platy Deaths... chemical filtrant involvement?   3/15/08 I have a platy problem. I've lost 3 platies in three days. First, here's my tank setup: 55 Gal Freshwater Community Tank -- Been up and running for about 18 months now. Population (Before Deaths): 5 Bleeding Heart Tetras 3 Orange Platies 4 Yellow Platies 2 Zebra Danios 2 Glowlight Tetras 2 Peppered Cory Cats 2 Otocinclus No live plants, a few rocks, some driftwood, and some aeration. Water Parameters (as of a few days ago): Temp -- 74F pH -- 7.4 Ammonia/Nitrites -- 0 ppm Nitrates -- 7 ppm KH -- 5 deg Phosphates -- 0.5 ppm <Water quality and compatibility should be fine...> A few weeks ago, I started controlling Phosphate levels, in an attempt to rid brown and black algae. <Mmmm, how?> My water supply has high PO4 levels (about 2 ppm), so I started putting Phos-Zorb in the filter. It brought PO4 levels down to about 0.25 ppm, but since then has started to rise due to regular water changes (~20% water/week). <Mmm, you might want to just filter the incoming/change-out water> A couple days ago, I noticed an orange platy couldn't swim 'he would just sink to the bottom, but remain vertical. He died later that day. Last night, I noticed a yellow platy with similar symptoms, but he would swim up for food. He would also stay at the bottom, and/or hide. His fins were severely nipped, so I figured he probably got beat up and was just injured. This morning, I found that yellow play dead. I also noticed another yellow platy hiding, but did not appear injured 'just hiding. I found him dead later this afternoon. I'm afraid there might be some sort of parasite or something killing off my fish. All other fish appear OK. <Mmmm, what fish/es if any, are new/er to this system... How recent?> I feed the fish tetra flakes every day, with the occasional day of freeze-dried bloodworms. All 7 platies listed above were purchased about 8 months ago. <Oh! They themselves are not likely a/the source then> Any help would be appreciated. Thanks, Aaron <I would remove the Phos-Zorb product, seek other means for algal control... Perhaps just some floating plant... Please read here re: http://wetwebmedia.com/FWSubWebIndex/fwalgcontrol.htm and the linked files above. Bob Fenner>

Opinion on Chemical Media in Planted Aquarium  2/4/08 Hi - I wanted to get the expert's opinion on chemical media containing carbon with ion exchange media (such as Chemi-Pure and BioChemZorb) and the planted tank. My fear would be scavenging too many trace elements and hurting the growth of my plants. I've used Purigen with great success, but have heard various rave reviews of the Chemi-Pure, and - to a less extent - BioChemZorb. Thanks in advance for your feedback. Your site is, by far, the definitive online guide for fishkeeping. Very truly yours, Stu <Greetings. I'm not a big fan of carbon in freshwater tanks. It does nothing that regular water changes don't do better. Carbon was most valued in the Stone Age of the hobby, where people deliberately avoiding changing the water. 10% a month was normal. The idea was "old water" was better than "new water". The big problem with old water is that organic decay in the tank produces organic acids that lower pH and turn the water yellow. Carbon adsorbs organic compounds, and by using carbon in a filter, the aquarist could keep the pH stable and the water clear. Nowadays we routinely change 25-50% of the water per week, so the dissolved organic compounds in the aquarium never reach a concentration where they are sufficient to cause harm. In terms of value, biological and mechanical filter media deliver more tangible results per cubic centimetre of filter space, and chemical media for buffering water chemistry can also be useful under certain circumstances. Finally, the active life of carbon (regardless of how it is packaged or what brand it is sold under) is literally a matter of days. One manufacturer of fish medications makes the point that carbon over 5 days old won't have any impact on their medication because it won't absorb sufficient quantity of that medication to affect the efficacy of the drug involved. That pretty much sets it out for you in terms of how often carbon needs to be replaced if it is to do any good. Carbon doesn't removed many inorganic substances, iodine is the only one of note, if I recall correctly. So carbon won't really do anything to the CO2, iron, magnesium, etc. that you need to keep plants healthy. The minerals at least need to be in their reduced rather than oxidised state, so won't be in the (oxygen-rich) water anyway but in the (oxygen-poor) substrate. The carbon obviously doesn't do anything to the substrate. So bottom line, in my opinion, is buy whichever you want since they're all a waste of money and don't make any difference in the big picture. Cheers, Neale.>

Questions on Activated Carbon Hi WWM crew, I have questions on carbon issue for fresh water usage. Hope you will clear my doubt and myth on this. Will it absorb vitamins that is being added to the water? Is it true that it will also absorb all elements in the water? Thanks in advance < Carbon removes lots of things. Vitamins and organics are the main ones but will also remove chlorine and some lead. I think there is an article on carbon by Dr. Tim Hovanec. Go to Marineland.com and look under Dr. Tim's library. I think he has an article on carbon. -Chuck> Cheers.

Runaway Carbon - 05/17/2006 Hi, <Hello.> I have a healthy (good pH, 0 nitrates, 0 nitrates, 0 ammonia) freshwater BiOrb containing a couple of Platy's and White Cloud Minnows.  When I cleaned it recently, some of the carbon pellets 'escaped' from the filter housing.  I had already cleaned - vacuumed & wiped the sides of the tank, and was in the process of changing the filter, when the 'escape' happened. I managed to scoop all the floating bits up with a net, but there are a few bits that have fallen in amongst the ceramic media on the bottom of the tank. The fish cannot reach them, and I felt I had disturbed my fish enough, so I decided to leave them there.  Now I am a little worried about whether or not they will affect my fish, and would value your opinion on the matter.   <Ah, no worries.  I would get them out when you can, as they will possibly interfere with additives to the tank, but no rush.  When the fish are chilled out and you can get a very small, fine mesh net in there, go for it.  Until then, don't stress about it.> Regards,  -Sharon <Wishing you well,  -Sabrina>

pH shock, FW  -- 03/18/07 Dear Crew, <<Hello, Kris. Tom here.>> Does a routine carbon change in my freshwater tank cause a pH shock and if so, how do I get around this? <<By 'pH shock', I'm assuming you're observing a significant rise in pH, Kris. Changing the carbon in your filter shouldn't affect your tank's pH levels. If this 'appears' to be happening, I'd surmise that it's occurring in conjunction with water changes, which can definitely affect your pH readings. If your water is inadequately buffered, pH can drop significantly in a short span of time. Even with adequate buffering in your source water, you can expect to see a drop in pH levels after a while. A water change, particularly if it's a large one, will send pH levels right back up. Kind of a pH roller coaster ride. You do want to avoid the temptation to chemically alter your pH in either direction. This typically creates more problems than it solves. A simple/safe way to maintain pH stability is by making smaller, more frequent water changes. Kind of takes 'Nature' out of the picture and puts the control back in your hands. Best regards. Tom>>  

Carbon Removal, algicide use...   7/28/06 I put an algae inhibitor tablet in my tank and it said to remove the active carbon when using tablet. How long am I supposed to remove the carbon filter for?? I don't want to screw up the process. <A week or so... algicides can be real trouble... Please read here: http://www.wetwebmedia.com/maralgcidefaqs.htm Applies to freshwater as well as marine... though there are inputs for the other, carbon... posted on WWM. I'd be reading there, testing your water daily, being ready to change out water... Do read re other means of algae control. Chemical means are the least favorable. Bob Fenner>

New Tank Questions II  1/1/06 Thank you for the quick response.  In the past I ran the tank without CO2 with a similar plant load and lighting, about 2 watts per gallon.  With CO2 at 8-10 PPM the tank has much more rapid plant growth, at least double.  Its more work but seeing the plants flourish and bubble oxygen is worth it. <Agreed>     My goal is to get off of the Chemi-pure.  I purchased both Seachem HyperSorb and Purigen.  I plan to try them and see if I can get off the Chemi-pure.  I have used Chemi-pure instead of standard carbon for many years. I would imagine I can get much better technology by now. I just don't know but I have always used some form of carbon.  A bad childhood experience made think it was a must.  I think back think I always overfeed the tank. < Think about what it is you want the medium to absorb. Chemi-pure absorbs almost everything, same as poly-filter.>    Again thank you for your time and your advice.  Ultimately I want my new large tank to be as much joy as my 100 gallon.  I also want ease of maintenance and redundancy in filtration.  Perhaps if I go with something that includes a Fluidized Bed Filter I should also install a UPS to protect against power outages. Regards, Freddy < Good luck and have fun with your new tank.-Chuck>       

Carbon and Plants  11/30/05 Love the Conscientious Marine Aquarist. Do you think that the addition of activated carbon to a planted fresh water tank, that I routinely add fertilizer to, will remove the fertilizer needed by my plants? John <Yes, and will quickly become inactive carbon as it does. Unless you are trying to remove a known chemical contamination I would not add extra carbon. Don>

Rinse That Carbon! - 11/25/05 Hi Again! <<Howdy>> Well I have finished my treatment with Cupramine and I am very happy with its results.  Now that I have basically done a 100 percent water change, added Bio-Spira and carbon, here is my question. <<shoot>> Might be somewhat stupid. <<Only if not asked.>> I bought a small pre-bagged pouch of activated carbon (from Hagen, it's AquaClear) and put it in the little Cascade filter but I realized that a lot of carbon "Crumbs" and dust came into the tank. I siphoned out as much of it as I could but I can't pin-point every spec.  Does this dust have any adverse effect on the fish? <<Nothing to worry about mate...next time pre-rinse the carbon under the tap to rinse away the dust.>> Thanks so much! -Jon <<Regards, EricR>>

The True Utility and Function of Zeolite 11/22/05 Hi, <<Hello.>> I was just reading the page on the following link http://www.wetwebmedia.com/FWSubWebIndex/fwchemfiltrants.htm and would like to take the time to clear a point up about Zeolite. <<Please do (especially after having read the post in question).>> Zeolite is not a name given to activated charcoal,  <<Carbon, activated carbon.  Charcoal is for the barbeque.>> but it is a compound mineral that is mined in different countries around the world. <<Yes, very true.>> Its main function in aquariums is to remove ammonia or other positively charged ions. It can be recharged by submerging it in salt water and then rinsing the Zeolite in pure water, for this reason it should never be used in a marine aquarium, as any ions that are naturally found in the Zeolite will be released into the aquarium. <<Well, this is more than I knew about this stuff (though I knew it was a mineral, such as dolomite is a mineral, and useful only in freshwater), and we can use all the good knowledge we can get.>> Regards Lorette Freese <<Thank you for this information, Lorette. Am posting this morning. Marina>> 

Is high ORP achievable with very green water?  9/30/05 Hi WWM crew! <Rich> I am trying to improve water quality and control algae in my 150g Malawi Mbuna setup. To that end I recently started injecting ozone through a protein skimmer, mindful of your guidelines/precautions in your ozone and ORP FAQs. In the past few days, however, RedOx potential appears to have skyrocketed from ~270mV to well past the safe range. RedOx potential as of this morning is ~440mV <Mmm, I would be careful here... and keep this ORP reading below 350> but green water remains in my tank. This is the problem. <?> I gather from this that 1) it is possible that high RedOx potential and green water are not mutually exclusive, or 2) my brand-new, cleaned and calibrated ORP probe is reading a voltage that is higher than actual. <Possibly... both can occur> I would very much appreciate your opinion as to whether I can continue to inject ozone at low dosage despite my not-so-sure ORP of 440mV until the algae is defeated. <Takes time... a few days to weeks...> Thanks in advance, crew. You do a great service to aquariumhobbyistkind. Regards, Rich Choy San Francisco, CA <Patience my friend... and do turn down that RedOx dial. Bob Fenner>

Tanganyikan Cichlids, Carbon - II - 09/16/2005 Thanks for the reply.   <You bet.  Crewmember Sabrina with you, this time, as so many of our folks (Bob included) are out at MACNA.> I checked out Eheim's website, and they recommend  running carbon short-term, to take something specific out of the water.    <This is the best/most common use, yes.> I've never relied only on biological filtration.  If I didn't run carbon on a regular basis, wouldn't my water not be as clear?   <Mm, only if you have something in the tank that continually discolors the water (like driftwood).  With proper maintenance, you should have no need for carbon except, as Eheim suggests, to remove something specific from the water (like discoloration from wood, undesirable chemicals, and emergencies where toxic substances may have been introduced).> I have always done 20% weekly water changes. <This is probably fine.  I would suggest to try running without the carbon for a while; it loses its efficacy after a few to several days, anyhow, so you really won't be "missing" much, I think.  Wishing you well,  -Sabrina>

Carbon Filtration 7/18/05 I need some instructions on how the activated carbon filtration works on a 150-200  gallon aquarium that's built  in to the back of the tank. < Go to Marineland.com and go to Dr Tim's Library. Look at the articles on filtration and you will see one on carbon that should answer all you questions.-Chuck>

Phosphate removal results - freshwater tank Dear Crew, <Glen> Here's another voice praising y'all for the invaluable service you provide to us in the hobby. Thank you for not paying attention to twits who don't want to take the time to read. <A minor irritation... from an extremely small minority of folks.> Thought you might be interested to hear my results in removing phosphates from my freshwater tank. We started out with phosphate buffers and fake plants in our 55 gal community tank. Over a period of several months, we replaced all the fake plants with real ones, and upgraded to 110W of light.  <Ah, good> The algae growth was pretty amazing at first, and as our desirable plants started growing and we increased their numbers, the algae started to at least slow down - the black brush algae pretty well disappeared, and was replaced with green and some thread algae. <Good point> I saw here and other places that excess phosphates made it more difficult to keep algae under control, and decided to do something to reduce the phosphates. I got an Aquarium Pharmaceuticals phosphate test kit, and the levels were off the scale - over 10ppm, but no telling how far over. <Yeeikes... anything over 1.0 ppm can be trouble> The test immediately turned a gorgeous midnight blue, and got darker from there. Went to the LFS, and the guy there asked me if I'd be willing to try a new product they were carrying, and tell him how it did. It was the "Marc Weiss Phosphate and Silicate Magnet". When I got home, I did my usual due-diligence and looked it up. When I saw that people weren't terribly impressed with most Marc Weiss products, I figured I was in trouble, but then I noticed that someone felt that the phosphate removal stuff was ok. At $35 for an eight-ounce jar, I really hoped it was more than ok! <Me too... this one is an "also ran"> I divided the product into two fine mesh bags, and stuck them in the cartridge of my Magnum 250. When I turned it on, I got a gush of rust-colored water (the active ingredient is ferric oxide hydroxide)... <Yes... the ingredient in almost all such products> ..that turned the entire water column an ugly reddish brown. Yuck! The color disappeared after about two hours. I tracked the phosphate levels over the next while. After nine days, there was finally a detectable difference in color in the test - still a midnight blue, but not quite opaque. Levels dropped slowly over the next week.  After sixteen days, they hit 2 ppm and stuck there for several days. It was pretty apparent that the product was exhausted. When I removed it from the Magnum, it had gone from its original deep rust color to an odd copper-blue.  I found some Seachem Phosguard on sale, and bought a two-liter bottle of it for $16 ($18?). After a couple of one-cup batches in the Magnum and another week, I got the phosphate levels down to around 0.5, which is what I wanted to do. <Great> In summary, the Marc Weiss "Phosphate and Silicate Magnet" did a yeoman's job of taking the bulk of the phosphates out of my tank. I'd thought about using the Phosguard from the start, but the directions on it indicated that it exhausts fairly quickly (which I've seen in using it on my smaller tank, which is in process now). When starting from a 2 ppm level, the PhosGuard did well at finishing the job, but it did take two batches to get it done. FWIW. Again, thank you for what you do. I'll send another donation in the next month or so.  Glen <Thank you for your keen input and kind, encouraging words. Bob Fenner>

Using ammonia/nitrate removing media during fishless cycle First of all I must congratulate you for your wonderful site. I have recently set up my 25 gal freshwater aquarium. I am using a canister filter, loaded with sponges for mechanical filtration, biofiltration media and Zeolite. <Sounds good> Currently, after 2 days running, I get the following readings: pH=7.3 , [NH3]=0.5mg/L, [NO3-]=12.5mg/l, [NO2]=0.05mg/L, KH=6, GH=3 Tap water from my area is hard and alkaline (pH around 8 and GH around 7). <Tank is cycling...be patient and don't add fish until ammonia, nitrite and nitrate are at zero> The aquarium is decorated with lava rocks and driftwood. <I'd be wary of using lava rocks...it is my understanding these leech chemicals into the water and are not suitable for ornamental aquarium use...> Is it the driftwood (and/or Zeolite) that softens the water and gives me a low pH value? <Driftwood will lower the pH, shouldn't be the Zeolite, which, to my understanding, is simply a brand name of activated charcoal> Is the buffering capacity of my aquarium enough or will I experience sudden pH changes in the future? <You will have to monitor this to see - I can't give you a pat answer.  How big is the piece of driftwood and what is the pH of your original tap water? If need be, you can use something like aragonite sand as a substrate to buffer the water...> I am planning to add a pair of Firemouths, a pair of blue Acaras and a Bristlenose Pleco (A. multispinis). The problem is that the appropriate water parameters listed on the Internet vary from site to site. What are the optimal water conditions to keep these fish? <You will always get different information depending on where you look.  I trust www.fishbase.org to have accurate info, along with others...in general, cichlids like water somewhere around 6.5-7.5 pH, and the Bristlenose Pleco would be fine in that range as well.  In reality, pH stability is more important than exact matching...> Now before adding the fish, I am planning to follow the fishless method to cycle my tank. <Wonderful! Good for you...> Is it absolutely necessary to add filter media from established aquariums? <No, this would simply expedite the process.  Not necessary at all.> Should I remove Zeolite from the filter? <No, leave it in place> Once the nitrogen cycle is established, should I use ammonia and nitrate removing media (such as AmmoChips/NitraZorb) or should I leave only the biomedia (BioStars) with their bacteria to filter the water? Will the accumulation of nitrate concentration at the end of the cycling process result in an algae outbreak? I have also read that it is recommended to keep the tank lit during the process. Wouldn't this normally aid algae growth? Should I add the Pleco after the nitrite level begins to fall, in order to keep algae under control? <I am not a fan of using chemicals to remove toxins.  Water changes will accomplish everything you need to do, from keeping algae at bay to completing the cycle.  I have always left my tanks lit during cycling, as the algae will also play a part in the cycle as well.  As long as you aren't running power compacts or other super-powerful lights, you shouldn't have too much of an algae problem, but do be aware that most new tanks have various algae blooms during the first several months they are established.  Again, water changes are your friend in this case!> Thanks. Spyros <Thank you, Sypros, for doing your homework and being such a thorough and thoughtful aquarist! Keep up the good work, Jorie>