FAQs on Marine Alkalinity 1 Related Articles: pH, Alkalinity, Marine Alkalinity, Understanding Calcium & Alkalinity, Related FAQs: Marine Alkalinity 2, Marine Alkalinity 3, Marine Alkalinity 4, Marine Alkalinity 5, Calcium and Alkalinity, Phosphate,  & FAQs on: The Science of Alkalinity, Importance, Measure, Sources, Use of Additives/Buffers,  Troubleshooting/Fixing, Products by Name:  & FAQs on pH: Importance, Science, pH Measure/Test Gear, pH Controllers & pH Buffers/Buffering, pH Anomalies (Troubleshooting/Fixing), & pH Products by Name, Manufacturer, All marine life is dependent to a degree on alkalinity, alkaline reserve/balance. Cuttlefish egg.  In N. Sulawesi.

Hi Bob,  I've been trying to keep my levels as stable as possible using only water changes and adding liquid magnesium (as this seems to be the main parameter I struggle to keep up) I'm using D-D H20 salt and do 15% water changes of around 50 litres per week. But, I'm still finding that most weeks my kH drops by 1 (it's usually 9 after a water changes then 8 by the end of the week but sometimes drops slightly below 8) I'm reluctant to use buffers, as I know that it isn't sustainable as it could lead to my kH rising gradually. I've been exploring balling lite but I'm still a bit perplexed by how to dose and I was never really very good at chemistry! Would a calcium reactor help keep everything even or will it just maintain just calcium? I do add coral grower and trace elements weekly but am I doing enough to keep everything stable? Thanks in advance Katie Advani   Salve Katie. Might I ask how you are adding to your Mg? Simple Epsom Salt (Magnesium Sulfate, MgSO4) addition is my fave'¦ for being inexpensive, effective and readily available. Next, the loss of KH, dKH can be due to a few circumstances'¦ most often due to livestock metabolism, uptake by biomineralizing life. In essence, overall processes in captive systems are reductive, acidic, with loss of alkalinity a common affair. And corals, calcareous algae and more can really use up a good deal of alkaline reserve (along with Calcium, Magnesium'¦), particularly in brightly lit, over-driven settings. You don't mention your livestock and/or feeding practices, but these may be an important part of the puzzle here, as might be inefficient skimming.                         I'm a bit confused re your reluctance to utilize a commercial buffer. I definitely would read up, employ one myself'¦ Best dissolved into new/make up water for when you do your weekly maintenance. I want to help you set aside your worries here re simple chemistry. You mention the use of a 'coral grower' and some supplements; I encourage you to spend some time with your in-print works and the internet reviewing the listed active ingredients, their interactions. Again, I would be using an 'all in one' (carbonate, bicarbonate'¦) buffer if this were my system.              Concerning the question of use of a calcium reactor, depending on the media you're using, melting down, mostly Calcium and Carbonate will be provided. There are some products that will also generate free Magnesium. IF you have a large system (hundreds of gallons) and/or a good deal of valuable biomineralizing life (e.g. stony corals) a calcium reactor might be worth considering. However, I'd gain a basic understanding, working of the system without one first.

 - Lowering Alkalinity, Follow-up - Hi and thanks for the reply. <My pleasure.> I have been using the same Tetra Test for several years and test exactly the way you have suggested. <Hmm... perhaps time for some new reagents.> I have always tested my change water for pH, alk and salinity before changing.  I use Instant Ocean and the alk usually tests around 14-16 dKH. <Have heard many reports of late of high alkalinity when using this salt... perhaps they have a wacky batch out there.> The pH of the change water is always around 8.3-8.4.  I have never tested my source water for alk but will now. <Worth checking.> Any other suggestions if my source water is high as well? <You may want to try and deal with this at the source, before adding salt. The process is a little time consuming and potentially hazardous if you go about it carelessly. You can use a weak acid, like vinegar... but is not wise to add wholesale. Rather add in small amounts and then test... wait a half day to a day and then test again. And go through this process a couple of times, testing and adding more acetic acid in very small amounts. Do not add the vinegar directly to your tank, and I'd try to avoid doing this to mixed water as well.> Anything else I should look for/do? <Start at the source.> Thanks again, Jeff <Cheers, J -- >

KH and dKH I have an Alkalinity test kit that measures in KH <carbonate hardness> and not dKH. (I think its KH, the measurement is in the 100 -120 range) I want to be able to translate that to dKH because that is what most recommendations are given in.<Alkalinity should be around 8-12 dKH> Is there an easy formula for this?<Found this link for you hope it helps http://www.chaoticreefer.com/TestKits/SalifertAlkalinity.htm >  Or can you provide a recommendation on alkalinity level for a reef tank in KH? <8-12dKH is recommended> Thanks.<IanB>

By The Numbers.... Dear Crew, <Scott F. your Crew Member tonight> I have a new 20 gallon minireef with 20 lbs. live sand and 20 lbs. live rock.  It completed cycling 2 days ago, and I go back for 20 more lbs. LR and the cleaning crew tomorrow.  I use DI water and Coralife salt mix.  I have salinity at 35 and SG at 1.026 (in an attempt to mimic natural seawater as best I can).  My salt mix tests out at a pH of 8.0, alk of 3 meq/L (or approx. 8.4 dKH), with a Ca level of 510 ppm. <Wow! That's really high....> This last figure seemed a bit high to me, but I thought maybe it will work out well once I put my LR and LS and critters in.  (I ran the system with just the salt water for three days before adding anything to get a good feel of all the equipment, evaporation, etc., as this is my first marine and reef tank.)  The current tank water tests out as follows: ammonia - 0, nitrite - 0, nitrate - 4 mg/L, Ca - 500 ppm, pH - 7.95, alk - 3 meq/L.  I am concerned about that high Ca and relatively low pH.  Hangers-on with the rock included several species of sponge (including a beautiful 3.5" pink vase sponge, orange ball, various encrusting and boring, red finger), several anemones (sponge, turtle grass) as well as a gorgonian of some sort and several other little mobile creatures (snails, crabs, etc.) and sessile things as yet unidentified.  I lost a couple of the sponges in the cycling, but want to keep the rest.  Anyway, I am afraid to use a 2-part Ca buffer to raise pH since my Ca is already so high. <Well, the alk is quite adequate...And is a good indication that your system can hold it's pH to a certain point...When did you take the pH reading? As you know, it is often lower right after the lights come on...> One more thing -- I have only been running my lights 5 hours per day until the cleaning crew arrives, so I know that is a factor.  Should I do anything at this point to raise the pH?  Just leave it be for a little while longer? <Yep- I'd leave it be...> I would use Kalk but w/ the 20 gallon and no sump, this would be really difficult.  Any help would be greatly appreciated. Thanks so much! Erin <Well, Erin- you're doing a great job with regular testing. However, if it were me, I'd do exactly what you're thinking...Give things a bit more time, and wait until you can ramp up the lighting for a longer photoperiod. Also, don't get overly fixated on specific "numbers", as we hobbyists tend to do...Yes, it is important to achieve certain minimum water quality targets, but it is not worth you tearing your hair out! Just relax and let your animals "talk" to you...If things are out of whack, they'll tell you in many ways- believe me! Perform aggressive and appropriate regular maintenance (water changes, etc). Just hang in there- You're doing fine. I'll bet that the pH will correct itself in time...If not let's talk again...Good luck! Regards, Scott F>

Calcium/Alkalinity Dance Hello again.  I have been having a problem that I hope you can help me with regarding the calcium and alkalinity in my tank.  I have read over all of your FAQ's and articles on the subject, perhaps there is something that I am missing.  My tank: 90 gallon FOWLR-- 25% water change every 2 weeks 3 clown fish; 1 regal tang; 6 small mushrooms; 145 lbs of LR. pH-- 8.25 to 8.45 Alk. 11 dKH (pretty stable) cal. 250 ppm Over the past 6 months I have been dosing Kalk via the slurry method and adding SeaChem Marine Buffer.  This has resulted in excellent coralline growth and other growth on the LR.  I used to add 1 teaspoon of Kalk before lights on every day and alternating: 2 teaspoons of Marine Buffer and 3/4 teaspoons of Kalk at midday (Kalk one day, Marine Buffer the next).  The reason for adding Kalk twice on one day and once on the next day was to not spike the pH too much).  2 months ago my calcium was a stable 340 ppm and my alk. was 11 dKH.  Wanting to slowly bring up my calcium levels (around 400 ppm) I started dosing 1.5 teaspoons of Kalk everyday before lights on and alternating-- 2 teaspoons of marine buffer and 1 teaspoon of Kalk at midday. I slowly increased these levels over a period of 7 weeks (I test weekly for cal. and alk.)  One would think that this would result in increased levels of calcium.  NO!  Now it is lower, 250ppm.  I have not had a snowstorm.  Nothing else has changed in the tank over the last 6 months.  Is my tank suddenly consuming more calcium?  Or is there something possibly wrong. My magnesium is around 1200 ppm, if that helps.  Thanks. <Well, it seems to me that you've got a pretty good read on what's going on in the tank. It's a real balancing act, as you know, to keep both high alkalinity AND high calcium levels (in fact, down right impossible for most people). I think that this is one of those cases where you'll have to be glad that you have good alkalinity, and accept the calcium where it is. The fact that your coralline is growing so well is a testimony that you're doing something right. If it were me, I would not get overly frustrated about it...Just keep doing what you're doing, monitor the water parameters, and enjoy your tank! Some might disagree with my assessment, but I think that you're fine here. Maybe not the technical answer you might have expected- but it seems to me that you are getting fine results...just not the number you want to see on the test kit...I'd relax...Good luck! Regards, Scott F>

Alkalinity Pool- kH question  Hi! By-the-way, you're a great crew!!! <Thanks kindly> I'm going to ask you one question: Month ago I was dripping Kalk - it did great job > my kH rinse from 7 to 10 {dKh} <very good to hear... as hoped/expected> Then I stopped for a week to see what will happen. kH rose to 8 so I started to drip again {1 week ago}... Why is my kH is still 7 and didn't move???? I'm doing everything like then but it don't 'want' to move... What cause that? My Ca was 410 all the time so I'm not worrying about it. <my apologies, but its not clear to me exactly what your question is my friend. Are you comparing/testing for carbonate and/vs. general hardness? If so... it is possible to have a slight discrepancy between the two although they are usually close/similar. Perhaps it is best to determine what your natural daily drop/demand is for these parameters... then test to see what the rate of delivery your present drip dose delivers is. You will then have an indication if you are dosing enough. Best regards, Anthony kH question I'll clear my question: Why my kH isn't rinsing even if I drip Kalkwasser? <Ahhh... yes. Understood, my friend. The reason is very simple... Kalkwasser only indirectly supports (although it usually does it very well) carbonate hardness by providing caustic (high pH) hydroxyl molecules which neutralize acids in the aquarium that would otherwise "chew up" your pool of carbonates (kH). But Kalkwasser does not actually deliver carbonates... remember it is a "calcium" supplement. For extra carbonates, you need to use a buffer product (containing sodium carbonate/bicarbonate). Aquarists typically dose buffer by day, and Kalkwasser by night. IN systems with a nice deep bed of fine aragonite sand, you may not need much or any buffer, and Kalkwasser alone will support both Ca and ALK. But in your case... it sounds like you may need to be adding a little bit of sea buffer powder too> I'm doing everything like before to push but it don't want to move... Best regards and happy weekend Peter <no worries... easily misunderstood... our tanks need calcium + carbonates to make calcium carbonate structures. Both must be kept in good supply and stable, else you will not realize growth. Best regards, Anthony> Alkalinity What should be the range of alkalinity in a salt water tank mine is 38 gallons <target 12 dKH for general care and higher if reefkeeping. Anthony>

Snowstorms Ca/Alk <it seems highly unlikely... are you confusing a simple temporary clouding of the water with the catastrophic "snowstorm"? A "snowstorm" is a sudden and severe crystalline precipitation of calcium carbonate that looks literally like snowflakes polluting and aquarium an is quite dramatic! Your calcium/carbonate levels plummet within 12-24 hours and it can be fatal to many, most or all livestock in the tank at times. When you say "snow storming" this implies to me that it happens to you regularly and such a thing is nearly impossible within weeks (gross neglect would be necessary). We should be clear on this term first.> Ah. Perhaps I am overestimating the significance of the crystallization I see. I used to see just a puff of white when I poured the stuff in that resolved in 5 seconds. Now I see crystals (like snowflakes ) that cloud about half the tank for about 5 minutes, then go away. The only chemical derangement has been the chronically dropping KH that DOES correct when I add a bunch more buffer. So maybe what I see as a snowstorm really isn't very important. It hasn't killed anything. Thanks :) <excellent my friend, and yes...agreed (and glad to hear it too!). An easy mistake when you haven't seen the other side (thankfully) to know what it looks like. Try diluting your supplements in a larger volume of seawater before dosing or add slower to reduce the cloudiness. In the meantime, do consider the two-part supplements. They are a little bit more expensive but work so very well! Kindly, Anthony> Tracy

ALK, Calcium Greetings! <Cheers, Anthony Calfo in your service> I have what seems to be a fairly successful reef which has a TON of money into it and all life in there seems to be well. I have an open brain, magnificent anemone, frogspawn, green star polyp, and about 10" in fish. Here goes: 125 gallon, RO/DI water, 6" 175w MH/VHO Canopy, 180lbs. live rock, wet/dry, carbon, heater, chiller, Aquacontroller II, Aqua-c EV-120. Water parameters: 80 degrees, 1.023 SG, Ammonia =0, Nitrites=0, Nitrates=<2, Cal 380-400, Alk 2.5 meq/l, PH 2.3 at night - 2.45 during the day,  <The alkalinity is too low and the pH is clearly a typo...resend please> My dosing schedule is: Monday & Tuesday dose 2.5 gallons/day of top off dosed with Seachem Reef Plus, Advantage Calcium and Reef Calcium, Tuesday and Wednesday - Reef Builder (raises carbonate alkalinity) Thursday and Friday, just advantage calcium, Saturday and Sunday, Reef Builder. Obviously the Alk is low and so is the SG. I am not dosing Kalkwasser.  <I strongly recommend Kalkwasser> What do you recommend to raise alk?  <common Seabuffer if using Kalkwasser or two part liquid supplements if using neither (like B-Ionic brand or Sea Balance)> Just keep doing what I am doing?  <heck no> Let me know your thoughts on just using the liquid and powder calcium chloride.  <calcium chloride should only be used alone in emergencies... it is plagued with problems for daily use in the long run> Should I supplement some Kalkwasser in the schedule?  <daily for optimum coral growth and saponification (improving skimmer performance)> If so, how often. Thanks! Adam <best regards, Anthony >

ALK, Calcium II Thanks for the reply Anthony! <very welcome> Follow up question for you or two. 1) Why is daily use of Calcium Chloride a problem? <accumulated chloride ions can skew the alkalinity/Ca dynamic.. making it hard to maintain alkalinity> 2) So, you would dose Kalkwasser daily and how often would you use a buffer? Is this an alkalinity buffer? <not a buffer directly, but reduces the amount of buffer needed in a system to maintain Alk while increasing Ca> 3) Do you see a problem with biweekly dosing of Reef Plus ( Vitamins and minerals for corals)? Actually they (Seachem) recommends just dumping 6 capfuls (for my 125) into the sump. <experimentally it sounds fine... I like regular water changes as much or better for this purpose. Anthony>

Alkalinity Hi Bob, me again. <Anthony Calfo in your service> Thank you for your previous help. I have a problem getting the Alkalinity reading below 140,  <not sure of the measure you are referring to here...ppm? Else, target through conversion a dKH of around 12, or approaching 4 meq/l> my other readings are as follows. 176 litre tank, Temp 24.5, S.G 1.024, pH 8.1, Ammonia 0, Nitrite 0.2, Nitrate 10, Phosphates 0.25, Calcium 360, Iron 0, Alkalinity 140.  <hmmm... the pH is also low (needs to be higher... like 8.3 by night and 8.6 by day)... your phosphate is also high enough that you should expect nuisance algae soon if you don't already have it.> The tank is four weeks old and I do a 20 litre water change every week, for some reason I am unable to get the Alkalinity down. There are two domino fish along with six red leg hermit crabs and six turbo snails. Could you please advise on what to use to get the alkalinity down to about <125. Many thanks Colin <Colin, high alkalinity is rarely a problem.. I believe you've been misguided on this point. Furthermore, you calcium is fine but just about on the low end. You may want to consider using a two-part liquid calcium supplement that will take care of Ca and Alk like B-Ionic or Sea-Balance. Best regards, Anthony> 

KH units I have a question for you and that is how do I lower my KH.? I have bought a new test and my reading is 240 mg/l thanks in advance, dab <I am unfamiliar with this scale. I have only ever seen alkalinity measured in German degrees of hardness (dKH) or milliequivalents per liter (meq/l). What brand is this and are there any conversions given with the kit? -Steven Pro>

Re: KH this is a Hagen carbonate and general hardness test and now I see there is a conversion chart it was hidden in the flap in the box you multiply reading times 0.02 to get meq/l I have a reading of 3.2 this is bad I think or at least very low? <not very low... in fact, just barely on the low end. Really nothing much to worry about. If you have a full reef tank... get the alkalinity up with regular additions of Seabuffer (tm) or two part liquid calcium mixes. Have faith, my friend. You're fine. Anthony>

Re: KH one final question <always ask...> if I use Kent SuperBuffer dKH and Kent turbo calcium will I be o.k. for now  <ehh... a bad habit to depend on calcium chloride for calcium unless you do an unbelievable amount of water changes (accumulated chloride ions can skew the dynamic with carbonates). Properly applied Kalkwasser has far more benefits. The buffer is fine... most brands are quite similar as tri-buffers (borate, carbonate, and mostly bicarbonate)> I have a full blown reef set up{55 gallon} well sort of not all the gadgets} and a 54 gallon mushroom tank <yes... do use Kalkwasser and consider a calcium reactor in addition in the long run. Much better and safer than chloride products. Especially so to protect the considerable investment that you have in the reef system (s). Kindly, Anthony>

Calcium/Alkalinity Hello Wet Web Media Consortium , Never know who will respond to emails . I am still having a problem getting my calcium levels past 380 after about three weeks of dosing with Kent A and B solutions . All other parameters are within tolerances . I only have Live Rock in the tank with yellow tangs . The tank is a 120 with a large CPR wet/dry/protein skimmer . Any suggestions would be greatly appreciated. <Use a Calcium Chloride solution to raise your calcium levels and then maintain it with the two-part solutions.> Also I've noticed that your Alkalinity levels in FAQ are being measured in dKH , my test kit measures in meg/L . What is the correlation between the two? <2.8 x meq/l = dKH> Thanks for the help you guys provide thousands of enthusiasts around the world . Richard Atkinson <You are welcome. -Steven Pro>

Alkalinity and pH Control Bob: <Steven today.> Recently I purchased a large calcium reactor secondhand from a local marine store (MTC Pro-Cal). I set it up on my 58 gal. reef (small in size compared to the reactor's capabilities!). I had it running for a couple days with very low input into the tank in order to avoid a sharp change in pH. However, within a couple days I noticed that most of my soft corals had closed up, with one torch coral looking like the tips had been burnt off! I also noticed a dead shrimp and some snails that were not moving, starfish with holes (lesions) in them, and mucus sloughing off the corals. My purple Montipora bleached out in a day. I am afraid I have done irreparable damage to the tank inhabitants. The catch is, I cannot determine the exact cause. The fish have not been affected. I did a partial water change with little improvement to the inhabitants. At the same time that I started the reactor I also added a product called "Stop Parasite", because of an Ich outbreak. The manufacturer says this product is completely safe for reef aquariums, and it can be added directly to the aquarium. I only added one dose (less than 1 teaspoon) and stopped because of the reaction of the corals. [By the way, would a UV sterilizer be the best method for eradicating Ich?] I placed activated carbon back into the sump. In any case, because these two things occurred simultaneously, I am having difficulty assessing which one caused the problem. I have a pH monitor on the tank. I noticed the pH range to be between 7.9-8.2 (could have been a time I didn't noticed a dramatic drop, but I have been adding more buffer in the hope to preclude a swing in pH). I just measured the alkalinity in the tank and it seems to be good (4.0 meq/L or 11.2 dKh). Could a dramatic increase in alkalinity cause this type of reaction of the invertebrates? The alkalinity in the tank before I set up the reactor was around 2.0 - 2.5 meq/L. As a note, I haven't calibrated the pH meter since I bought it (I know, a bonehead move). I will do so shortly. <Your information about pH is completely useless when measuring with an uncalibrated machine. It is utterly impossible for me to say if the readings are accurate, significantly lower, or higher than the numbers you gave.> Do you know anything about this "Stop Parasite" product that is supposed to be so safe in reef systems? Aside from purchasing a UV sterilizer (another expensive purchase), I have tried unsuccessfully to get rid of Ich in my tank. Could a dramatic swing in alkalinity cause an "acid-like" reaction where the corals and other invertebrates appear "burned"? <I do not know which caused the problems in your tank. Whenever first hooking up a calcium reactor it is imperative that you watch the calcium, alkalinity, and pH very closely for the first several weeks until you have the unit dialed in correctly. Secondly, I would not use any Ich medication on a reef tank. It is much better to quarantine all new arrivals prior to putting them into your main display. Unless, the Ich broke out and you have not added any new fish for several months. Then you may have even more problems.> Thanks for your response. Tim <With more and accurate information, perhaps I can be of more assistance. -Steven Pro>

Ph, Alkalinity, Oh my!! <cheers, Sean... Anthony Calfo working, thinking and ...er, lost my train of thought> Hi to the fine folks answering the questions with/for Bob. I know I would be a slime algae farmer by now if it weren't for this site and chat forum!! Many thanks!! <very welcome> I have a problem with low ph. It hovers around 8.0 (+ - .5). <rather low indeed> In addition, my alk is usually pretty high--14dkh. this is down from 20 dKH I "achieved" through improper calcium reactor operation (I guess). <agreed> Anyhow, I can not get my ph to be higher. I've aerated the RO makeup water and use Tropic Marin salt mix. I recently bought Anthony Calfo's book (very informative and helpful), <thank you!> to add to my library of Bob's CMA (great!) <awesome...very informative> and Julian Sprung's Vol 1(very good) <an old stand-by and wealth of info> among others and feel I have a good understanding of the intricate dance these elements do, however I cant get them to "dance" properly in my 6 month old 110gal (hopefully) reef tank. The facts: (other than I can't spell) <hehe... that's OK, I can't sing... but I can dance> Lights; 2 metal halide 250 watts on at 9 A.M and off at 9p.m. <a bit long for halides especially 250's... ever notice that some. many of the corals "close up" early?> At 6pm last night ph was 8.17 dKH - 11 calcium - 320 <get this up with Kalkwasser towards 400ppm and watch your pH follow> nitrates< 10mg/l Phosphate < 2mg/l Redox 327mv Temp 79 1 sohal tang 3", 1yellow tang 2.5", 1 hippo tang2.5", 2 -3/4" inch clowns, 2 blennies, 1 Heniochus 2", 2 bubble tip anenomes (it just split 2 nights ago), some Acro frags, green star polyps and a few polyps of xenia on a snail shell. My theory: I feel as though my mistake with the calcium reactor raised the alk to such a high level that it precipitated out other essential elements aka magnesium (a ph helper?). I haven't tested the magnesium level (cant find a test kit locally) but have noticed my once widely growing coralline algae has stopped growing and is disappearing. <possibly... but your free calcium level isn't thrilling, and if that way for a while, more likely the cause of poor corallines> I think it would still grow despite the lower calcium levels albeit slowly. I'm thinking that I'll have to add Kalkwasser to raise both the ph and calcium but I really don't want to do this unless I have to. <you are correct, and it really isn't that bad. Refer to the section in my book on simple dosing by direct slurry with careful pH testing/confirmation... a $40 pH pen would come in handy... or a meter, better yet> I bought the calc reactor to avoid this supplement routine/cost/ tedium.  <please remember that reactors are for raising alkalinity, NOT calcium. Even Daniel Knop (or the Knop reactors) admits Kalkwasser supplementation of reactors is desirable/helpful> I currently have the Calc reactor at a 10bubbles/min.  <what is the pH of your effluent?> Also, I feel as though I am maniacal about tank husbandry, now stingy with the food (for which I feel bad but just cant tell when enough is enough), 10% water changes weekly, ozone injected (which should help ph but not in my case) skimmer emptied daily, and overflow pre-filters wrapped in poly filter stuff changed weekly. The water is pristine, colorless, beautiful to look at! I want to add some macro algae to suck up any extra CO2  <shouldn't be necessary or even possible if you have sufficient aeration and water movement in display...besides, they can be noxious to some coral> but I have no luck in sustaining it. It quickly dies and my water quality is shot!!  <because your water quality is too good...<smile>> I doubt there is that much problem CO2 in my system but something is depressing the ph. <agreed... confirm by testing pH of glass of aquarium water, aerating it, and then testing again...if pH does not raise, you have little/no residual CO2> Questions: What is the usual (your experience) ph of RO water out of the purifier? <very acidic... well under 7.0> What is depressing the ph? <you may have a case for using some baking soda...carefully> Actually it is about 8.2 at the time salt is added and aged. <too low... aim for 8.4-8.6> Stop the Calc reactor for 2 weeks or so and see how things progress? <nope...ne knee-jerk reactions, please. Likely to make things worse> If ph isn't improved what to do then? <punt> Add the Kalkwasser for a while? <yes...most definitely> What are your thoughts?--I'm lost <that's OK...I've been lost for years. I can't even find my tukus with both hands. Anthony>

Adding Buffer or Calcium? Anthony, <Cheers, John> Thanks for the clarification. Only problem is that I too have a reef system albeit a small load right now of a Pinked Tip Anemone, Hammer coral, feather duster, serpent star, star fishs etc. and about 90 lbs of live rock. Everything is doing quite well, but maybe I should not do the baking soda thing? <really two different things and purposes. Baking soda is largely for increasing pH (tweaking pH in an otherwise normal/healthy tank with other buffers/carbonates as one gets from med/hard tap water). It is easy to use and monitor. If that is your primary goal and you are using tap water (not demineralized R/O or DI water) than please use the baking soda at the prescribed CMA dose. If however, an aquarist IS using purified water (lacking buffers) and/or has a known deficiency in alkalinity in the water (naturally soft tap water for example) then sodium bicarbonate alone will not serve a reefkeeper well. Most commercial buffers (like Aquarium Systems Seabuffer) are "tri-buffers" (borate, carbonate and admittedly mostly bicarbonate) and better suited for increasing and maintaining pH (from the baking soda) as well as ALKALINITY (the buffering ability of water). If you haven't had the displeasure <smile> yet of studying the difference between pH and Alkalinity, then this may be part of the confusion. Back to the "story"... reef aquarists generally want/need to put buffers AND calcium into their system and neither one alone (baking soda or Kalkwasser) will usually do the trick. I hope this hasn't confused matters further. Please do follow up if you need clarification. Nonetheless... the bottom line is that hard tap water may not need to be buffered, and baking soda will give you the extra pH you need... and purified water is not buffered, and needs something more than just bicarbonate. Kind regards, Anthony> John

Re: Algae problems - Please help Anthony, Thanks for the advice.  <quite welcome> What do you recommend that the dKH be at? 11-12? <yes...11-12 dKH would be fine...with a free calcium level over 380ppm as well there wouldn't be much to complain about> I had used SeaChem Reef Builder in the past but I think that I wasn't using enough or, the lack of strontium made it ineffective. I was also using C-Balance. Is there a product that you have had success using? <Once alkalinity and calcium are both in a reasonably good range... using the two part mixes is very good, just expensive.> I am using CaribSea pink Fiji aragonite fine sand. Should I just replace the whole thing or just take the thickness down to > 1/2 "? <Yes... if denitrification is not a concern/desire...else 3+"> I am not too convinced my skimmer is working effectively. I used to have an ETSS in sump reef devil. It just didn't seem to be doing the job correctly. I have just purchased a LifeReef Venturi skimmer. Again I purchased an "in-sump" model, for some reason I cannot get it to work effectively. I was using the in-sump models because of space requirements.  <in sump works best only if you have a skimmer box working as a standing overflow from which directly overflowing water is collected into a static vessel. Fluctuating sump levels are nightmares for skimmers> I am now considering a AquaC Remora Pro HOT and getting away from the sump for a few reasons. I had seen an article on a web page that had done a comparison between the CPR Bak-pak and the Remora Pro, both were used on a 38 gallon reef and the results were awesome on the remora. The second reason is that because of the fluctuation of my sump level evaporation), my current and previous skimmer performance would not be consistent. I would suggest staying away from in-sump models.  <actually easy to modify...simple diagrams on the net and in my book for doing so. You can then continue to enjoy the space savings. Tunze has an even better in sump skimmer that has a 4"X4" foot print and only needs 11-12 inches of water> I am also having a hard time dialing in for a thick effluent. (I think this attributed to the water level as well in the sump). <agreed> Lastly, the Remora is just plug it in and it works, obviously you would have to adjust the collection cup for skimmate consistency. < I still like Tunze and Euroreef skimmers better> Regards, Keith Broadbent <ciao, bub. Anthony>

High Alkalinity and Calcium Yep...test kits were bogus Anthony, <Greetings fellow blueberry eater> Thanks for your response. i had my water tested today by one of the local dealers with completely different testing equipment and the results are as follows. Ca 560, PH 8.0, Mg 1900, ALK 7meq/l . i guess the test kits i have are worthless. What do you suggest for remedies? <yes... not a surprise from the previous numbers reported. The solution is not crystal clear considering the complexity of balance with dissolved organics in seawater. However. step by step, we know that your calcium is artificially and dangerously high, and that the pH is rather low. Alkalinity is not terrible, but a bit on the low side as well. Lets begin with a relaxation on calcium supplementation and enough dilution from water change(s) to bring your calcium closer to 400. When water changes get your readings for calcium between 380 and 425 ppm, and alkalinity between 8-12dkh...start using a two part liquid calcium/Alk supplement as per directions. In most cases you should be able to resume a more traditional chemistry. Wane off of the two part if you prefer dosing separately. But know that the 2-part mixes are quite ideal for balance and their only disadvantage is price <smile>.Don't worry about the pH during the process too much... it should fall into place naturally with the correction. Best regards, Anthony> Chris

Re: High Alkalinity and Calcium Anthony, Thanks for your expertise, I will follow your directions as noted... however you said that 7meq/l was low? was that correct? isn't that like 19.5 dKH? <Ahhh, my apologies good sir.... I read through that part of your last e-mail too fast and thought the reference was already to dKH. Indeed, you are not at all low...but rather a bit high! Thank you for keeping me on my toes <G>> ONCE AGAIN THANKS!!! CHRIS <my pleasure. With kind regards, Anthony>

Ph/alkalinity Hello & (Thank You!) to the tag team answering Bobs fish tank e-mail questions, many of us greatly appreciate this effort. <Appreciate it... hehe, we're grateful that folks are tolerating it <smile>. Seriously...thank you. Anthony> My question is about Ph. I started running a calcium reactor about 8 weeks ago and had the effluent ph set at 6.8 (after reading Bobs faq's on this topic). My tank ph always hovered around 8.2, never below 8.0 or above 8.25. <indeed... a nice piece of equipment and your pH needed to be a bit higher> I'm still wondering, after reading the stored FAQs on this topic, how I can raise the ph to be in a more acceptable level. My dKH now, after refilling the reactor with Carib sea ARM and some old coral skeletons on top is 20 dKH in the tank. <whoa!!! Please retest your alkalinity with another test kit. You are in a very dire straight (no... not the band Dire Straights, although now I have "Sultans of Swing" in my head which is not likely to leave anytime soon) if this is even accurate! Natural seawater is 6-7 dKH, but most reefs fare better at 7-10 dKH (Sprung/Delbeek) and SPS dominant tanks can even be a bit higher (towards 12 dKH). You are in serious risk of precipitating free calcium from the severe imbalance of carbonate in your system (like a reverse snowstorm from the common crystalline carbonate precipitation from Kalkwasser abuse). If this happens, you just might kill most of the living creatures in your tank within 24 hours of a precipitous event. But do not make a knee jerk reaction either... back off of the reactor (what is your bubble count on the effluent?) and do some small but frequent water changes until you get down towards 12 dKH. It isn't easy to maintain high free calcium concurrently, but at nearly 400 ppm you have managed to do so and are at great risk for it>  I've slowed the drip rate from the reactor to bring this high dKH down.  <brother...this has to be monitored closely from go for the first couple of weeks until you get it tweaked> Calcium by the way is at 396. Before the Calc. reactor the DKH was always around 14 but the ph was 8.0-8.2. <agreed...something had to be done with the pH> The tank has been up and running 6 months and the specs are; 110 gal with 30 gals in the sump. The main tank has about 115 lbs of live rock and about 2" of aragonite "sea floor" from Carib sea.  <see other posts or write back but a 2" substrate is problematic in the long run... not deep enough for anoxic activity (denitrification) but too deep for aerobic activity. The rule is 1/2 inch or less or three inches or more... never in between> In the sump I have ~ 30 gals of water with ~ 15 lbs live rock, 20 lbs of a pre packaged live sand and 3lbs of Red Gracilaria (?spelling) "Tang Heaven" algae. <cool> I run a Turbo flotor 1000 Multi and inject ozone for an ORP in the main tank of 340 - 400.  <nice...and reasonable> I change 5 gals of water every week that is aged using RO water and Tropic Marin salt mix. <hmmmm perhaps the source of your original low pH problems: did you aerate the R/O water for 12-24 hours before buffering it (mixed completely) and then later salting it. If not, you wasted buffers in the salt mix by not off-gassing or neutralizing carbonic acid from R/O water... and your 2" sand bed is hardly a significant buffer> I add 10mg of Seachem iodide every other day <very good> The livestock in the tank is; 2 juvenile false perc clowns, 2 fire fish, 2 juvenile Heniochus, 1 juvenile Hippo tang (2"), 1 yellow tang(2"), 1 small bubble tip Anenome, 1 serpent star, 1 long spined urchin and 2 nice sized corals; elegance and hammer. with 3 small frags of Acro. The water parameters are: ammon=0, nitrite=0, nitrate is non detectable using FasTesT, 0 phosphates, dKH =20, Calcium= 396, Temp 77 degrees. <I'm not a high temp fan... but you could come up a bit higher...78-82F> I feel as though the alkalinity is sufficient enough to hold my ph to a desired level but getting it the desired level is the problem for me. <yes...above comments> I always feel I'm too generous with the food but the fish go nuts, acting as though they are starving to death. Only one looks thin, a "heiney" but not sickly. <honestly...feed small portions freq and as much as you can without causing nuisance algae and nitrates> the poly filter I have around the over flow pipe shows no sign of excess food and is changed weekly. Sorry for the length of this e-mail but I wanted to give you the full picture so you be well informed before offering your much respected advice. Any help would be greatly appreciated. <you have your work cut out for you, my friend. Anthony>

And Steve's Reply to the above question... Hello & (Thank You!) to the tag team answering Bobs fish tank e-mail questions, many of us greatly appreciate this effort. My question is about Ph. I started running a calcium reactor about 8 weeks ago and had the effluent ph set at 6.8 (after reading Bobs faq's on this topic). My tank ph always hovered around 8.2, never below 8.0 or above 8.25. I'm still wondering, after reading the stored FAQs on this topic, how I can raise the ph to be in a more acceptable level. My dKH now, after refilling the reactor with Carib sea ARM and some old coral skeletons on top is 20 dKH in the tank. <This is pretty high, about twice as high as it should be.> I've slowed the drip rate from the reactor to bring this high dKH down. Calcium by the way is at 396. Before the Calc. reactor the DKH was always around 14 but the ph was 8.0-8.2. The tank has been up and running 6 months and the specs are; 110 gal with 30 gals in the sump. The main tank has about 115 lbs of live rock and about 2" of aragonite "sea floor" from Carib sea. In the sump I have ~ 30 gals of water with ~ 15 lbs live rock, 20 lbs of a pre packaged live sand and 3lbs of Red Gracilaria(?spelling) "Tang Heaven" algae. I run a Turbo flotor 1000 Multi and inject ozone for an ORP in the main tank of 340 - 400. I change 5 gals of water every week that is aged using RO water and Tropic Marin salt mix. I add 10mg of Seachem iodide every other day The livestock in the tank is; 2 juvenile false perc clowns, 2 fire fish, 2 juvenile Heniochus, 1 juvenile Hippo tang (2"), 1 yellow tang(2"), 1 small bubble tip Anenome, 1 serpent star, 1 long spined urchin and 2 nice sized corals; elegance and hammer. with 3 small frags of Acro. The water parameters are: ammon=0, nitrite=0, nitrate is non detectable using FasTesT, 0 phosphates, dKH =20, Calcium= 396, Temp 77 degrees. I feel as though the alkalinity is sufficient enough to hold my ph to a desired level but getting it the desired level is the problem for me. I always feel I'm too generous with the food but the fish go nuts, acting as though they are starving to death. Only one looks thin, a "heiney" but not sickly. the poly filter I have around the over flow pipe shows no sign of excess food and is changed weekly. Sorry for the length of this e-mail but I wanted to give you the full picture so you be well informed before offering your much respected advice. Any help would be greatly appreciated. <It is not unusual for people to experience lower pH levels when using calcium reactors due to excess carbon dioxide in the display tank. Dial your reactor back to allow your alkalinity to come down to an acceptable level. At the same time, add calcium only products to keep your calcium level when it is. You are going to have to monitor your conditions closely. Once you have both where you want them, slowly increase the CO2 to maintain these levels. Hopefully, then you will no longer have excess CO2 in your display. Also, look up the excellent writings of Craig Bingman on the topics of calcium, alkalinity, reactors, and Kalkwasser. -Steven Pro>

Messed up tank Hi Bob, Merry Christmas! I need help with my 60G reef acrylic tank .. I was stupid enough to dump too much buffer (water+Kent buffer) into it last week and half of the front glass is now coated with "white stuff". <Yeeikes!> I tried scrapping it off with my credit card and with the cleaning pads but still there is a lot of "white stuff" left. Good thing is I am actually moving this weekend so I would get a chance to give it a good clean. Do you know of any good way to get the "white stuff" off? <Not w/o emptying the tank... gently wiping with dilute acid (like vinegar, acetic) on a sponge, or better, swishing successive washes of it (white is better) onto the panels... Or letting time go by... it will wear off... Don't scrape! Bob Fenner> Thanks again! Brian

Hagen test/ tang /DOC questions Greetings and happy holidays Bob! I have written before about the 100 gallon tank that has the hair algae problem (440 w of VHO, T1000 skimmer, 2' sand bed, 100 lbs. LR, a decent amount of feather Caulerpa in tank and lots of Sargassum). I did take your advice and added a Salarias fasciatus a week ago. He's a funny little guy. . . so far he has managed to make the pump returns spotless and the tank walls but I never see him eat on the LR.  <Time will tell... whether the species on the LR is palatable to this animal> Other than a few mushrooms and some button polyps there is no other live stock. Therefore, the 2 3/4 month old tank has never been fed. <Mmm, sufficient nutrient for much life can/does come from seawater, tapwater, substrate, the rock, other organisms being "cycled"...> The skimmer is still pulling a considerable amount of DOC out of the water and I've done a 40% water change in the last month. Yep, I still have hair algae and there's a fuzzy kind of algae that grows on the front glass. Any suggestions for getting rid of the DOC?  <Just keep doing what you're doing> More water changes?  <Some... if the nitrates become too much (tens of ppm)> Right after Christmas I plan to add a purple tang (after quarantine) . I currently have" 0" readings for all the bad things and a 4 for nitrates. Does DOC affect tangs? <Affects all living things> I also want to add a few aquacultured Sarcophytons. Is the hair algae bad for them?  <Not necessarily... their presence may in fact reduce the algal growth> Lastly, my KH test is from Hagen. Every reference I find refers to KH in terms of small numbers (1-12 etc.) My test expresses the KH as mg/l. How do I convert to the numbers used in reference materials. My current KH is 120 mg/l. Thanks for all you do Bob. Have a happy and safe holiday season. <KH can be converted to mmol/l of CaCO3 by dividing by 17.9 Bob Fenner> David Dowless

Aragonite i have a 75 gal trickle overflow with a 20 gl sump that is large enough to handle a 15 tank and is working good water spec are great the only problem i have is that my ph stay at 7.9 or 8.0 i add Kalk by slow drip but after the one gal bottle empties it goes back to the 7.9 - 8.0 i would like to know if the original aragonite that i put is the tank eventually loses its punch  <All substrates do> or maybe i don't have enough  <A distinct possibility> got about120 lbs live rock i got about an half inch under the rocks and about one inch and a half in the front of the rocks fine to med grain should i had more and if so how much do you think this would help i have a med to heavy load of live coral and about six small fish would increasing the amount on the bottom be the solution THANKS <Maybe... but look into more of your background in water chemistry here... You'd be better off with a "two part" supplement system to bolster your alkalinity (give up the Kalk)... and best with a simple calcium reactor. Please read over these areas on our WWM site, starting here: http://www.wetwebmedia.com/watrqualmar.htm and onto the many linked files, FAQs listed. Bob Fenner>

Alkalinity, pH, Buffer Robert, <<JasonC here giving Bob time to pack for his upcoming dive trip.>> Because of your website, I have begun to study the issue of pH, alkalinity and buffer in seawater. As one step in applying this info I've bought an alkalinity test kit with the following result: ~5-10 ppm carbonate From what I've read this is too low for a fish/reef tank. However, absent the test data, I would say my tank is in perfect harmony! <<so far, so good>> Here are my particulars: 100 gal icecap 660 driving 3 x 48" NO full spectrum and 1 actinic (upgraded a month ago from NO) < .05 ammonia, pH 8.4-8.6, my pH has been the same for years. salinity right on haven't tested nitrate/nitrite in a long time don't know calcium but the Halimeda is beautiful and large, 4 happy fish ~3" one open brain coral (1 month old) <<this one would love to have more calcium>> lots of Halimeda, Caulerpa, modest live rock monthly water change of 5% My questions: Should I be concerned about alkalinity as my pH has been fine? <<if not today, then tomorrow for certain - yes you should be concerned>> Should I be concerned if I want to add more hard coral or zooanthids sp.? <<most definitely for any stony coral or Tridacnid clam. But sure, even soft corals with their Sclerites need some calcium to grow.>> If I should be concerned do I adjust it with 1) off the shelf elixirs 2) mix up my own with soda ash and baking soda (see Moe) 3) add new substrate 4) increase frequency of water changes ? <<if you have the necessary equipment to precision mix yourself a batch, then who am I to stop you? On the other hand, do you want to experiment on THIS tank? Is the difference in cost worth it to you if you have a small accident - after all, Martin Moe has a lot of tanks to play with. I would personally just use Arm & Hammer baking soda - should be more than sufficient to boost your Alk. Regular [roughly every six months] substrate augmentation will also go a long way to helping. As for the water changes, this is really just a personal choice but I would do a 10% change every two weeks - probably won't affect your alk either way.>> Is the reduced alkalinity due to consumption by the Halimeda or the drop off in production by the substrate/rock in time? <<I would say consumption by the brain coral, secondarily by natural cycling in the substrate - unless this tank is over a year old. How long has the tank been running?>> Sorry I missed the last SDMAS meeting as I understand from the group emails that it's a testament to modern technology! Maybe I'll make it to one in the near future. Thanks for all your help! <<Cheers, J -- >> David A. Bidwell

Re: Alkalinity, pH, Buffer JasonC, Thanks for the quick reply. You guys are amazing. <<well thank you very much, *blush*>> To answer your question, the tank is 7 years old, but the enhanced lighting and the brain coral are new. I have added new substrate only once (and have never vacuumed the bottom - maybe that's why the algae are happy). I'm due for some augmentation? I'll try the baking soda. Could you recommend a dosage? Thanks again!! <<well, there's not really a "patent dose" as it were, as different tank condition will yield different results. My recommendation [always] is to add a small amount and then measure a couple of times over five minutes or so, and then if needed, add some more and measure again. This is exactly the way I do it on my own tanks, and granted I'm using an electronic pH pen to speed the tests, but it will keep you within tolerance if you take you time in this fashion. For the 100g tank, I'd guess a quarter to a half teaspoon at a time would be a good start, and make sure you measure pH constantly. Also, as a final note recall that a tank's pH shifts throughout the day. You might want to spend a day taking measurements to get an average reading before you start trying to shift the pH/alk. Good luck, J -- >> Dave

Alkalinity Question Bob, All my tank readings (Nitrates = 0.0, pH = 8.2, Calcium = 420, SG = 1.024, etc.) are fine but my alkalinity is only about 1.4 - 1.5 milliequivalents per liter. This low alkalinity, I suspect is the cause of my red coralline algae bleaching to some extent. <Yes, definitely> Plus I'm worried about the few small corals I've added to the tank (Star Polyp, Mushroom, etc.). I know that eventually I need to get a calcium reactor <Not necessarily... what is the cause of the low alkalinity? Use of Kalkwasser? No soluble substrate? Too many biomineralizing organisms present with boosted lighting?...> but between the cost and the fact that a 90 gallon tank only has so much room left in the stand, I've decided that after reading you're website, I may be able to get the Alk. up into the desired range by adding simple Baking Soda. My question (finally!) is how do I add the stuff. I know I should mix it in water, but how much should I add at one time, and how frequently should I add the mix??  <About a teaspoon per actual twenty gallons of water, dissolved in system water as you state... measure alkalinity next day...> I appreciate your help (again) and I look forward to meeting you at one of the future San Diego Marine Aquarium Society meetings. Phil in San Diego <Yes. The twelve hundred gallon system meeting residence this week was very nice. Bob Fenner>

Buffering/lighting Hi Bob, My tap water does not have a lot of buffering capability. <Do you need, want more? Can be augmented easily> When I do my regular water changes (7 to 10days), the tank water has a pH of 7.8. I use Instant Ocean Salt and my replacement water has a pH around 8.2. I believe that the shift in pH after water changes is stressing my system.  <Good point.> I have started to use Kent Marine's Super Buffer and now my pH stays at 8.3 and. Alk = 4 meq/l. Is this method of keeping up alk/pH up a good idea or would the two part supplements be a better choice? <Two part would be better.> I did read the article in FAMA as requested by you about the Ice Cap ballast running NO fluorescence. I remembered reading that article years ago and another (same concept) with a plant tank. It really sounds like they are having tremendous results with NO tubes and VHO ballast. My main question here is with tube replacement. Ice Cap says 6x longer life. The recent article in FAMA state that regular replacement of the tubes have been unnecessary. Also in FAMA with the other article on the plant tank he state that he has been running the same tubes for years. Now what puzzles me is that this is exactly opposite of what most say. Hmmm? <The use of electronic ballasts in these cases does extend effective lamp life as far as I'm aware, but don't know about six times, definitely not indefinitely. You can test for intensity, spectral make-up over time... or just observe your plant livestock for changes. Bob  Brad

Re: UV sterilizer and a start up reef tank-One more question Thank you for your insight. One more question. My pH is fine (8.3ish) and my kH/harness (10-11) is fine. My alkalinity is low like 1.8 to 2.0. How can my hardness be fine and my alkalinity not. <Mmm, other compounds that contribute to hardness, but not the Calcium, Magnesium... carbonates, bicarbonates of alkalinity present in your water. http://www.thekrib.com/Plants/CO2/hardness-larryfrank.html> Do I need more buffer and does it matter what kind (NaHCO3?) or will that make my pH to high? What is the relationship between hardness and alkalinity. My local fish guy says not to worry about alkalinity and just test for hardness, but many things list the alkalinity that inverts like. Have any insight? I am obviously no chemist. Thanks again. <My insights on these topics is posted on the WetWebMedia.com site. Please refer to the indices there or use the Google Search feature there. Bob Fenner> Christine

pH and Alkalinity balance Hi Bob. Thanks for being so approachable and one of the most knowledgeable aquarists in the business. <You would do the same, given a similar background, circumstances> I have a puzzling question...I have a 180 gallon reef tank. The problem seems to be keeping the alkalinity up above 6. Whenever I add buffer to get the alkalinity up, the pH seems to go up over 8.6. If I add buffer I can get it up to 9-12, but then the pH seems to keep rising. Even as the alkalinity falls, the pH stays up around 8.4 or 8.5. Is this necessarily a problem? <Mmm, no... considering that you don't have nutrient concentration problems (like high, detectable ammonia)...> Any advice you could give me on this situation would be greatly appreciated. <There is much to be elucidated here re the interaction of principal chemicals (mainly carbonates, bicarbonates and biominerals, i.e. Calcium, Magnesium, Strontium...), supplements, adjuncts, gear that affects same... and resultant pH... Suffice it to state here, that you are likely adding the "co-factor" in the way of a chemical preparation that is resulting in this anomaly... you could counter the effect by adding carbon dioxide... a possibility... or switch to a calcium reactor to keep all factors stable and "about right"... or elect to "do nothing" which will likely be fine. Please avail yourself of the information on the site WetWebMedia.com re these issues, and if you'd like, supply input about your supplement practices, set-up... and we'll work into specifics. Bob Fenner> Thanks and keep up the good work! Joe

Re: Specifics on ph-alk question Hello again Bob, Thanks for the reply to my original question concerning ph-dKH balance. You said to get back to you with specifics, so here goes. 180 gal. reef/ 3+inches live sand/150lbs.? live rock/40some asst. pieces coral/ 8 fish [largest are a yellow & purple tang]./asst. stars&snails, etc. Equipment-4 160 watt VHO bulbs powered by icecap ballasts/ photoperiod: actinics 11am-10pm/50-50s 12pm-9pm/Berlin skimmer w/Rio 2700pump/ U.S. aquar. wet-dry w/Iwaki pump-1300 gph return. I do a 45gal. water change every 3 weeks. I use R.O.-D.I. water for water changes/make-up water. As for additives, about all I add is Kent turbo calcium [1tsp. per day] to try and keep the Ca level up, and SeaBuffer as needed for alkalinity. I manage to keep the Ca level about 360. Every now and then I'll add iodine, strontium, or magnesium if the corals look as if they need something, but this is rare, as most of the time they look great. On any given day the ph will start out at 7.9-8.0 and rise to about 8.4-8.5, even though at times the alkalinity will drop to 4 or5. I would like to keep it up around 9 or 10, but as i said , as I add buffer it wants to push the ph up over 8.7. Nothing seems to be adversely affected, but it is really puzzling me. I really appreciate your taking your time to think this over and hopefully come with an an answer. Thanks a million, and keep up the great work. <Will try/endeavor to do so. What you have is a semi-classical case of "yo-yo'ing" of adding simple, soluble sources of alkaline and co-precipitating calcium (et al. alkaline earth elements/compounds... the Mg and Sr) additives... If you saw the energetics of the supplementing and the money being turned into white sediment "cement" in your system you might scream. Do consider either "going with" a simple two part (like B-ionic) alkalinity/biomineral treatment scheme BY ONE MAKER (wow, that's bright), or making the light year jump to a calcium reactor here. "IT" is your supplement practices that are (self)defeating you here. Please read over the Marine Alkalinity, Calcium et al. related sections on our site: www.WetWebMedia.com for more peoples anecdotes, explanation of what is going on here. Bob Fenner> Joe

Low dKH Bob: I just finished reading most all the Q & A's on alkalinity, pH and calcium and now clearly understand why I never became a chemist. <Really? Have endeavored to keep all at minimum, simple terms... and the concepts, formulas are actually quite simple... taken a step at a time...> But I see how these must work in harmony together much like barley malts, hops and yeast.  <Good... and tasty comparison> My dKH is constantly low. I add Kalkwasser which I now understand lowers the dKH. With a lower dKH the pH was also dropping which in combination I suspect contributed to my problem of my coralline algae bleaching.  <Yes! You're "getting it"> I was under the misunderstanding that adding Kalkwasser took care of everything.  <No... "it's" just calcium hydroxide... actually drops out carbonates, bicarbonates, even other alkaline earth minerals (e.g. Strontium, Magnesium)... and the hydroxyl radicals... let's not get started on these today> I use RO water to top off, about a gal a day, which I have not been adding anything to. Because the pH of the RO is very low would this constant addition on a daily basis bring the total pH of the tank down and the constant addition of the Kalkwasser on a daily basis bring down the dKH thereby further affecting the pH?  <Mmm, well "doesn't bring down low", but by not adding alkaline reserve... doesn't boost buffering, raising of pH... "fighting" the reductive (acidic) influences in a captive system...> And the simple question......should I be adding sodium bicarbonate to the top off water? <Yes, a good idea... at least this... if not a more complete "buffering, pH boosting" medium/prep.> My strategy is to slowly increase the dKH by adding a buffer and KH builder until I reach around 10 dKH. Keep adding the Kalkwasser to keep the calcium around 400, and add sodium bicarbonate to the top off water each day to maintain the constant dKH. Does this sound like a reasonable lay persons explanation and plan of attack, or has the combination of barley malts, hops and yeast thoroughly lowered the entire chemistry of my brain? <Hah! Well mine too if this is the case... Your plan sounds good, workable. I would proceed immediately. Bob Fenner> Thanks for any help Jim

Alkalinity Dear Sir, I have a 4-weeks old set-up live rock tank. Before I set up this L/R tank, I had sent four days to go through your articles. They are great and useful. <Thank you my friend.> Recently, I have got the following information. Light - Power Compact 2 Watt/Gallon Ammonia, Nitrite, Nitrate - Close to zero Salinity - 1.0225 PH - 8.3 Alkalinity - 8 dKH Calcium - 450 ppm For growing coralline algae, do you think I should raise the alkalinity to 10 dKH, 11 dKH or 12dKH? <This would be better... but might well "cost" you in lost biomineral... see you mention your means of supplementing below> Currently I am using Coralife Calcium Supplement to raise/maintain Calcium level. If you suggest me to raise alkalinity, what brand do you think is safe and can use in junction with Coralife Calcium Supplement? <Mmm, would actually leave your levels as they are now... If was raising, would seek out the same companies products... And in the longer term possibly employ a calcium reactor for pH, alkalinity, biomineral content...> Because I know Coralife Calcium is a good product and safe to use. Thanks, Joan <Be chatting. Bob Fenner>

Alkalinity Dear Sir, For most cases, I know that it is better to buy a Calcium Reactor for balancing both calcium and alkalinity. But my tank is way too small, only 23 Gallon... <Mmm, likely so> In my case for growing coralline algae, is my calcium level at 450 ppm imbalanced with a alkalinity of 8 dKH? <No.> What is the best combination reading for calcium and alkalinity? <400-450 ppm, 10-12 dKH... but other factors are as important... like magnesium concentration... good to develop an "overall perspective" and understanding here> What brand name of alkalinity buffering you think is the safest one and can in use with Coralife Calcium supplement? <Coralife, SeaChem, Kent, Tropic Marin, Salifert, Knop... similar in composition...> What do you think about Seachem's Reef Builder? <A good product. Bob Fenner> Thanks, Joan

Help? Question Hi, I have an question to ask you if you don't mind. I have a 55 G reef tank that has been set up now for about a year. Everything is testing fine but my alk. is testing at 5.00 mEq/l and my ph is 8.0 How can my ph not be higher than this value if my alkalinity is high?  <Easily... these measures are not directly positively correlated. Alkalinity is a measure of.... resistance to downward movement of pH... pH is simply a static value... a place... one can be high, the other low...> I'm trying to get my ph to a stable 8.2. I did accomplish this for a time with Proper PH 8.2 buffer but it dropped back to 8.0. My calcium is about 460.  <Ah! Likely your focus on driving the biomineral content of your water is your real nemesis here... self-caused. Please read through the various sections on pH, alkalinity, calcium... posted on our site: WetWebMedia.com and accompanying FAQs pages> What is causing my ph to drop if my alk. levels are high? Please help... thanks <You can only help yourself... give up your fixation on any one given value... the linearity of your thinking is the source of the "trouble" here. Bob Fenner.>

ALK levels Hello Bob, Just found your site today, it's awesome. <Thank you> I had a question about ALK levels and what they should read when measured; should they measure 5.5-6.0?  <Hmm, somewhere around 7-9 degrees KH is okay, (equivalent to 2.5-3.2 mmol/l... 8-12 degrees is better... 15 is too high, will likely cause trouble with precipitation, uptake of biominerals (alkaline earth matter)> Also what correlation does ALK have with Calcium levels and PH. <...! A very large topic my friend. Please study these topics, FAQs on the WWM site, and seek out the references mentioned there. In particular, the coverage of simple marine chemistry is well treated in Baensch Marine Atlas, volume 1> Just in case you need the info: Tank: 65 Gallon Acrylic Lights: VHO\Compact Mix 3VHO for Daylight (one of which is super Actinic) and 2 Actinic Compacts for Dusk-Dawn. Live Rock: 90Lbs Still in Cycle phase (2weeks) Wet Dry with build in Skimmer (works well) Thanks in Advance Matt Hunt <Bob Fenner... whose later academic education was in aquatic pathology...>

High dKH levels Hi Bob, Rick your reefing friend here again. If you'll remember, I wrote to you last week about a very high dKH level in my 180 gallon tank. I have just added a calcium reactor 2 1/2 weeks ago. My readings are. Ammonia, Nitrite, Nitrate all 0. (I have 200 lbs live rock). Calcium 350, Mag. 1300, Strontium 10, Alk 24 dKH. Temp 79-80, S.G. 1.025. You suggested boosting the co2 so I went from a effluent ph of 6.5 to 6.2 and left the flow at a steady broken stream. I am using Salifert test kits. It seems that my dKH is going the wrong way. My calcium in the last two weeks has gone from 120 to 350 but my hardness has gone through the roof. You mentioned that this excessive hardness can be a problem, in what way?  <Precipitation of biominerals... direct malinfluences on livestock... Do consider trying another source of carbonaceous material to melt down, returning the effluent pH to something nearer the mid to upper 6's> I use Kent Magnesium, Molybdenum & Strontium & Tech I Iodine additives on a weekly basis. <In addition to the reactor? I would drop these for now> What should I try next to lower the dKH or should I just continue to let things run as is. <Look for a "softer" smaller granule size feeder stock> As always, your advice and guidance are priceless. Happy Birthday and good luck with the move. <Thank you my friend. Bob Fenner> Rick

My 180 Gallon Reef Tank and High? Alkalinity Hi Bob, Because I didn't receive a response to this message, I assumed it got lost so I am resending it in hopes that it finds you in excellent health and enjoying life. <Hmm, thanks for resending... Didn't receive...> Rick Hi again Bob, Rick your reefing friend here. I just added a Precision Marine CR-622 Calcium reactor to my system which includes the following: 1-CR-622 calcium reactor using ARM media 1-1/4 H.P. chiller to maintain temp at about 79 degrees 2-40 Rainbow U.V. sterilizers, (Dual Mag drive 24's returning to opposite ends of tank through 1" lines) 1-Aerofoamer 830 protein skimmer 1-55 gallon Rubbermaid Brute sump with about 30 gallons water 1-30 gallon refugium connected to sump 1-6' PFO fixture w/3 x 250 watt 10,000K M.H. and 4 x 96 watt PC actinic Effluent from reactor at 6.5 and dripping into refugium in a steady broken stream. Ammonia, Nitrites, Nitrates, phosphates undetectable. Tank has about 1 1/2" CaribSea Aragonite sand and refugium has about 3" of same. Tank has 100 lbs live rock with another 100 lbs coming next week. I have the following fish. 1 Emperor Angel 4", 1 Naso Tang 5", 2 Banggai Cardinals, 1 Coral Beauty 3", 7 Green Chromis, 1 B & W Banner 4", and 1 Copper band 4" All fish doing extremely well thanks to you helping me beat HLLE in Emperor angel. My Alkalinity as measured with the Salifert test is well over 16 dKH. (Test kit only measures to 16 dKH so I am estimating 22 dKH because it takes another 1/2 syringe to evoke the color change.) My calcium level is at 260 using the Salifert kit. The calcium reactor has been running for one week. Finally my questions. Is the extremely high dKH a problem?  <Mmm, yes... could be...> If so, how can I bring it down? <Try increasing the carbon dioxide flow... lower the pH of the effluent from the reactor...> My calcium started at 120 before the addition of the calcium reactor and has steadily risen over the week. Will the system balance out over time and get my readings more to where they should be? (Calcium 400-450 and Alk 10-12 dKH.) <Should, yes...> Thank you very much for your time and trouble in answering all the questions you receive week in and week out. I can assure you your friends in this hobby greatly appreciate your sacrifices. One of these days I would like to buy you a cool one and talk about diving.  <Done!> Maybe in one of your favorite diving spots just after you and I and who knows who else has just finished an excellent day of diving. You reefing friend Rick <Be chatting, and diving soon I hope, Bob Fenner>

Alk real high hey again this jay a friend of the( kirbster) my alk is 17 dKH. Kirby said this real high he also said to just let the tank alone don't add anything . put the ph is like 8.7 tank has been set up about 7 months now i do like to keep it clean i was doing water changes every 2 weeks is this to much. i have nothing special on it fish are doing fine coral is great. how can i get this down i do use a R/O for water changes. suggest anything! thanks Kirby said high!!! <Hi back... take a read through our site: www.WetWebMedia.com under the alkalinity, pH, biomineral sections and FAQs... much to be said here. Bob Fenner>

Alkalinity and Sand Stirrers Good day Mr. Fenner... Thank you for all of your help in the past. Recently I discovered a problem with low alkalinity in my 48 gallon reef aquarium. I have also been having a huge problem with nuisance algae (diatoms, hair, bubble). Since, I added the CPR BakPak II (w/o bio-bale) I have noticed a huge improvement in water clarity, and it seems that the algae bloom has slowed considerably. Regarding the Alkalinity issue, I was getting a reading of 6dKH but after a 15 gallon water change, and one dose of buffer/alkalinity supplement (Kent SuperBuffer) my Alkalinity is reading 13dKH. Is it possible/likely/safe for such a drastic change in alkalinity?  <Hmm, possible... not likely with "one dose"... and not safe for many true/stony corals> My inhabitants seem fine, actually my hairy mushrooms are standing and swelling more than ever. <Ah, good> On a slightly different note, I've got a 3 1/2" bed of live sand that is still getting a coat of diatoms, and what I suspect may be a form of blue/green algae, or possibly cyanoBACTERIA. <These titles are used interchangeably... same organisms> It's not red/purple so I'm leaning toward BGA. Not very attractive, and my clean-up crew isn't getting paid this month (the blue hermits take their pay in astrea snail flesh, not cool!). <no> I've been considering some form of sand stirrer but am having trouble weighing the options. I get the feeling that you don't recommend the brittle stars, horseshoes, sand sifting stars,  <Some of the first are okay, and the latter in the form of Archaster is excellent><<Mmm, not such the opinion nowadays. RMF>> and you don't seem too hot on cucumbers (not the salad variety). I think bullet gobies or sleepers may be a possibility but they are quite hard to locate in my vicinity. Do you agree with these choices, or are there any other suggestions as to how to stir the sand and not allow the algae to sit?  <There are a few other choices... but these will do> I've been concerned that the sand stirrers would deplete my DSB of beneficial critters.  <This won't happen> So far my NO3 readings have been undetectable so the NNR, and conservative feeding schedule seems to be working. I appreciate your candid advice. Jason...the guy who says "My head hurts and my hands are hands are prunish but my mushrooms are lookin' better each day" <You're doing fine my friend. Bob Fenner>

Alkalinity, KH, etc., etc. Good day. I have been drawing upon your expertise lately, and am eternally grateful for your help. Without going through all of the particulars (again!?!) I have been having a water quality issue. I have a huge diatom bloom that is not only unsightly, but is driving be loony. <This does happen... the diatoms, lunacy...> Lately, it has been so bad that the water is clouding up, and you can't even see the back wall of the aquarium when looking in the front. I don't have all of the essential test kits (yet) so a trip to the local fish store was in order. After the test, I was informed that while nearly every water parameter was perfect (reasonably), my KH (alkalinity?) was too low. It was in the 6dKH range and he informed me that it should be more like 14 dKH. Would this cause my algae bloom, and resultant cloudiness??  <Would possibly contribute to it yes... higher alkalinity would favor other (perhaps less loathsome) algal types> The proposed resolution is to add a buffer/alkalinity supplement (Kent SuperBuffer), and protein skimmer.  <Oh! The protein skimmer will REALLY help> I purchased the CPR BakPak II and set it up last night. I also added a small mechanical filter to one of the powerheads. This morning the tank was crystal clear, and I had a nice soup of skimmate in the BakPak. Looks kinda like cream of broccoli soup, w/o the cream or broccoli. Yuk!  <Don't drink it! For sure.> The last question is, should I remove the bio bale material in the BakPak?  <Good point, question... we remove it from these ourselves... so, yes> I have a 3 1/2" DSB, and 50lbs LR. Since my NO3 level is at or near 0ppm I don't want to start up a NO3 factory. I noticed that there is a difference between the BakPak II and the BakPak IIR. This is namely a lack of bio bale, and the output tube looks different. Any info is appreciated. <Please write the fine folks at CPR (cprusa.com) re this...> From the guy who says..."Why-come the ocean makes it look so easy?" <Because it is? Bob Fenner> Jason

EGAD -- KH and GH Off the Charts!!! Hello Bob! Glad to have you back (though I truly appreciate Lorenzo's efforts, too!). <He was and is fabulous... a gentleman, computer scientist par excellence, and a pet-fishionado> Hope you had a wonderful trip! My tank is in it's 5th month. All of my fish stock are doing very well. I have: 1 false percula, 1 blue velvet damsel, 1 bicolor angel, 1 tomato clown, 3 fire fish, 1 blue damsel, 1 falco hawkfish and 5 very tiny hermit crabs (6mm width, maybe). They all seem to get along very well. I recently lost my bubble-tip anemone (just never seemed to adjust well to the tank) and my pencil urchin (he seemed very healthy, then up and died. Upon inspection, it looked like something was picking between his spines). <Possible> A quick rundown: 55 gallon long marine tank, crushed coral and live sand bottom, soon to house live rock (as soon as I can afford a protein skimmer), with a Fluval 304, 2 Penguin powerheads (1 - 550, 1 - 660), Venice-styled power compact lighting. My parameters are pH = 8.2, Nitrites = 0, Nitrates = 7ish, Ammonia= 0, Specific Gravity = 1.023. I clean my sandbed weekly, but make sure to leave some stuff for the crabs and the angel. I do water changes using well water that is pre-adjusted with salt, tap water conditioner and stress coat. The salt that I use is purported to have very low mineral content. I recently went and bought a test kit for KH and GH. Well, much to my dismay, these figures are OFF THE CHARTS! I literally used 1/2 bottle of the GH test drops without turning the water color to get a reading. KH was readable, but about 5x what it should be according to the charts in the test kit. <Wow...> So, my question is, what is the best way to adjust my water hardness down. <To ascertain the source (likely your source/tap water), and dilute the old water with new made up of much less dissolved solids (if it is the source water, you may want to look into a reverse osmosis unit for your drinking and cooking uses as well). Have your tapwater checked out, and your test kits through a sample tested at your local fish store> I was contemplating doing 15 percent water changes 3x a week, but if my water is too hard, this won't make a difference. I've seen that there are softener pouches, but wasn't sure if these would hurt my fish. Will adjusting it too quickly hurt my fish? <No need to make sudden or large adjustments here> Also, why have these extreme water hardness conditions not seemed to affect any of my fish? <They're remarkably adaptable, much more in ways than humans credit them> Their fins and scales are very healthy, they all have voracious appetites and are constantly out and about in the tank. Could it have contributed to the deaths of my urchin and anemone? <Yes, much more so than the fishes> Any help you could give would be great. Thanks a million! Deb Colella <As I stated, have your testers tested, and your tap... if these are not faulty and to blame, let's continue with this discussion. Bob Fenner>

High ALK but Ca is Ok. Clown comments. Hi Bob, You'll remember me as the one who you are always threatening to get a bigger tank. I'd have to sell my first born, if I had a first born. :-)) <Hmm> I'm confused again by the Ca and Alk tests. I was getting low pH (around 8.0) so I my LFS, and this is one I trust, suggested I use buffer everyday until it gets to 8.3. This was done. However the buffer I have is also a dKH regulator. I didn't expect it to spike the Alk. Anyway this is what happened. <A pH of 8.0 is not problematical... > The pH reads at around 8.2-8.3. Ca is 490. Alk is 6 mg/L (I think you multiply by 2.8 so it would be 16.8?) I think this is too high?? <Are you sure this isn't "milliequivalents per liter"? Otherwise a bit high, yes... will "come down" on its own...> But the Ca is ok and pH is ok. BTW, everything else is ok. Last time I tested: Ammon. 0; Nitrites .0; Nitrates trace (well under 10); Phosphates .0 I'm using SeaTest and FasTest. Anyway, should i be buffering with something that doesn't effect the ALK perhaps? Also I'm using an Ecosystems, not sure if that has anything to do with this. I think the pH tends to be low as I am using DI water. <Would at the very least use less of what you're utilizing... no need for the high values in all you report... Cut back on supplementing.> I just picked up two False Percs from a LFS that is going out of business to do only tank maintenance. This must be a booming career. :-)  <Yes, in many places> Anyway thanks to you I knew how to handle things. I put them in a quarantine tank (where they will stay for three weeks minimum) and dipped them in buffered H20 and Methyl blue. I would not have had a clue otherwise. <Hmm, again> In the excitement of great prices I forgot to ask if they were tank raised or not. (So at least I didn't do *everything* right! :-} ) I did later and found they were not :-(. Still doing ok, but that was only Saturday. I sort of assumed they were as they were all in a tank together, and seemed pretty happy with the arrangement. I assumed wild caught Clowns would not like this. Anyway just a comment that I guess that assumption isn't the case. <These are social animals when small... with lack of competition for anemone host/s... become territorial with size/growth, differentiation (the "winner" will turn into a decidedly larger female)... Bob Fenner> --Jane J, beta testing life

Alkalinity follow-up Hi, >Alk is 6 mg/L (I think you multiply by 2.8 so it would be 16.8?) >I think this is too high?? ><Are you sure this isn't "milliequivalents per liter"? Otherwise a bit high, yes... will "come down" on its own...> Yes, you are probably right. All those m/l whatever's are confusing. <Easily done...> >>I would not have had a clue otherwise. ><Hmm, again> BTW, did you know you are saying hmm to everything lately?? Are you going for your shrink license? <Will resist... can't Mmmm, now, that's better.> Repeat and happy customer and admirer :-), <Be chatting. Bob Fenner> --Jane

Alkalinity Bob, A few weeks ago you had been helping me with an office tank (75gal reef w/~65 lbs live rock) that had an outbreak of ich. (again, thank you for your help!!!) I had lowered spg to about 1.017 and raised temp to about 84 while treating the fish in a separate tank. I have since replaced the fish and brought the spg up to 1.022 and temp to 80 about 2 weeks ago. <Ah, good> Since removing and then replacing the fish everything seems fine, except a small bubble tip anemone that doesn't seem to want to open up quite all the way despite a maroon clowns constant attempts to open him up!) I attribute this to two things, first I upgraded lights from 80 watts of normal fluorescent to 260 watts of pc lighting (1/2 actinic 1/2 daylight) I cycled the lights, gradually increasing the time they were on and now the actinics run about 14 hours and the daylights 12. Could the anemone still be getting used to the stronger lighting?? The new lighting has been in place for about 3 weeks. <Yes... give this animal time... you do feed it I assume.> My second question is that since bringing the spg back up to normal, I have only been able to record an alkalinity reading of 2.5 milli/eq/litre. This tank averaged 3.2 before I removed the fish and treated the main tank for ich with the environmental manipulation. Could the low alk be affecting the anemone??  <Yes> I have a couple of derasa clams that are fine and all corals are fine. Calcium is about 400ppm and Ph is steady at 8.3. I have been doing a weekly 10 gal water change instead of every two weeks, but have only been able to get the Alk from 2.0 to the 2.5 reading I have now. I also have a money plant (Halimeda sp.) that is turning pale green to white, I assume from the low alkalinity. <Again, yes> My question is should simple baking soda restore the Alk to where it was before the lowering of spg? (prepared in purified freshwater and slowly added)  <Worth trying, yes> I also have some Red Sea brand ph buffer that I have not tried yet. Would I be ok in just adding it as per the mfg. instructions instead of the baking soda? <Yes... it is principally sodium bicarbonate...> (It claims that 100ml will raise alk of 40 gallons from 1.7 to 2.2) I only add calcium with trace elements on the weeks that I don't do water changes since I use a reef blend salt that has the calcium and trace elements in it, and I am very conservative in my additives.  <This is wise and smart> Once I re-establish a high alk should it stay high?  <Hmm, no... there is a net loss in captive systems due to driven biomineralization... in your case by clams, other life... as well as reductive events (acidifying influences) that nick down pH and alkaline reserve> In the first 4 months of the tank I never read an alk below 3.0. Finally, how much of a change in Alk is too much to quick? <A few tenths of milliequivalents per liter a day is fine> Your help once again is greatly appreciated!! Kris, PA <You're welcome my friend. Bob Fenner>

Question on buffering water Hi Bob! <Howdy> I just took some readings on my tank yesterday and found the following: pH = 7.2 Nitrate = (approx.) 30 ppm GH = (approx.) 107ppm KH = (approx.) 36 ppm I am satisfied with all those parameters except the KH. I'd like it to be higher to avoid unstable pH. I'm trying to stabilize the tank with soft water and neutral pH. I want to get skilled at keeping these conditions because I want to set up a discus tank one day. I'd rather not learn by killing such beautiful, sensitive fish, so I'm practicing on hardier fish that can handle a wider range of parameters. <Good ideas> Questions: What do you recommend I do to increase the KH without increasing the pH? <In your case, most cases, either some higher dKH tapwater or simple baking soda, sodium bicarbonate... slowly, in pre-made solution... dripped in...> What's your opinion on using a neutral buffer? I have heard that some of these buffers contain phosphate, which can lead to algae problems. <Some of them, yes... try the baking soda...> If you think buffers are OK, will you please recommend a neutral buffer product? <Hmm... I would rather not... as the formulations do change... and am posting this to our website: www.WetWebMedia.com... for an indeterminate length of time...> I've heard that you can add baking soda to increase KH, but does this also increase the pH? <Yes, slightly... but this should be fine... in the case of using captive bred, reared discus...> Thanks, Doug <Be chatting my friend. Bob Fenner>

Alkalinity Dear Bob, Right now I'm in California but I grew up in Rhode Island and I'm proud to know you're from my home state! <A fine place... now suburb of NY I'm given to understand...> We just introduced 3 hermits and 5 damsels to our 125 gallon aquarium yesterday. The hermits only move intermittently and got active during feeding the fish. We're worried that they're not constantly moving but only move intermittently. One just ran across the tank. At one point last night that same guy was upside down for a while. Is this normal for them? <No... not normal... do have periods of inactivity (not collective), but pretty much out "picking" at material all day long...> Could this be abnormal behavior related to our alkalinity level? A few of them are hanging out near the bubble wand. We use Coralife salt mix and our PH has been consistently 8.1. Alkalinity is 2. Tullock said that low alkalinity makes creatures have trouble with respiration.  <Yes, this is so... and very likely a contributing cause here> Do you think we should add bicarbonate or should we just sit tight?  <I would add a mix of carbonates, bicarbonates (and a little borate for good measure) here... pre-mixed in some of your system water... slowly... unless you feel very comfortable with "making your own", do use some "store bought" alkalinity/buffer here...> We have brown algae (diatoms) and green algae. This is a relatively new tank since our nitrite spike went down to zero a week or two ago. The damsels are very happy and eating heartily. <Likely the "cycling" process "used up" a good deal of your waters alkaline reserve...> Our filtration is a trickle with carbon and mechanical canisters. <Trickle/wet-dry filters are also notorious for this action...> Thanks, Allyson <Be chatting, Bob Fenner, who suggests you read over the alkalinity, pH and biomineral sections and FAQs (if you have time) posted on the site: www.WetWebMedia.com>

Depleting Alkalinity & Calcium Hi Bob, Once again I am seeking your help and expertise on a continuous and disconcerting problem I have with maintaining alkalinity and calcium stability. A Drastic depletion occur on a daily basis (alkalinity drops approximately 0.2 to 0.3 meg/L per day and calcium drops approximately 20 ppm per day as well). <Not unusual circumstances in "boosted photosynthesis" tanks... biomineral, alkalinity being used... rapidly> To combat this problem, I am currently performing 5% weekly water change, <May need to increase this... maybe to ten percent> dripping R/O water mixed with baking soda to elevate alkalinity (saw the suggestion on your website, although it appears to be a temporary solution) <Yes, and just a stop-gap measure> , and administrating ESV calcium directly into the tank every other day. I am very concern with the rapid depletion of elements and any suggestion/information to rectify my problem will be greatly appreciated. <In two words: calcium reactor... saw twelve Knop reactors (Hey Daniel, you owe me schnitzel!) at a friends LFS yesterday...> Below is a list of my current livestock inhabitants, water parameters, and filtration methodology in a 90 gallon tank (recently converted from a F/O tank): Fish: Majestic Angel---doing great and thriving for 8 months! Yellow Tang Invertebrates: 3x Cleaner shrimps 24x Turbo snails 12x reef hermit crabs 1x Wellsophyllia 1x Finger leather 2x Cynarina 3x Mushroom Water Parameters: Ammonia = 0 ppm Nitrite = 0 ppm Nitrate = 10 ppm pH = 8.2 Salinity = 1.025 Alkalinity = 2.8 meg/L (drops 0.2 to 0.4 meg/L per day ?YIKES!) Calcium = 340ppm (+/- 20 ppm)---similar drop compared to alkalinity'?approximately 20 ppm per day (double YIKES!!). Filtration: Wet-dry ETS protein skimmer 100 pounds of live rock---thinking about adding ~ 20 to 30 pounds. 40 pounds Aragonite sand Miracle Mud Ecosystem by Leng (recent additional'?hopefully will help with water stability). Supplements: ESV (2 parts calcium and alkalinity) Kent Trace Elements Kent Iodine (drip methodology---weekly) Kent Iron/Magnesium (drip methodology---biweekly) Kent Strontium (drip methodology---biweekly) Additionally, can you please give me any recommendations with the usage of supplements (frequency, quantity, and product); I am not getting the desired results especially with the Kent products. <These are good products, in a good line... entirely miscible, no bad interactions... Would look into Tropic Marin's BioCalcium product if you are going to stick with the rest of the Kent's line... But do strongly encourage you to look into a calcium reactor... the simplest, easiest, safest, and least expensive-in-the-long-term method of maintaining/optimizing pH, alkalinity, biomineral content. Bob Fenner> Thank-you for the time. Regards, Dan

High Alkalinity Hi Bob, I have been measuring my alkalinity/dKH with a Salifert test and getting very high numbers - alkalinity consistently around 4.5 meq/L and dKH 12.4 - 12.8. Everything I've been able to read only addresses low numbers and recommend dKH between 8 and 10. Is this dangerously high or does it just mean my PH will be that much more stable?  <Not dangerous... actually of benefit in a few ways... including pH stability> How can I lower it? Do I want to? <Stop adding buffers, biomineral supplements would be best... increase CO2 input (if you have such), just let time go by and the reductive events in your system (all captive systems) will bring it down... I would do the latter. Not to worry> I have a four month old 60 gallon tank with 45 lbs live rock 20 lbs live sand, skimmer, temp 78F, Nitrate 10 ppm, PH 8.3, Salinity 1.0225, Calcium 450 ppm. I add Calcium, Iodine, Strontium & Molybdenum once a week. My LFS didn't seem familiar with this situation and said not to worry about it, it will come down in time.  <Good idea, best> They also recommend changing 25 gallons/month which I think is high by anyone's standards (except those selling water =:o) I'm currently changing 10 gallons a month. <I'd change five or so every two weeks... and do look into buying your own reverse osmosis device for home and pet-fish use> Thank you, Brian Battles <You're welcome my friend. Bob Fenner>

Low Alkalinity Hello Bob, I have a problem (I think) with low alkalinity. I looked through my books at home and your site, but couldn't find anything on my situation. I have been testing my water every day to try and find the answer. Here goes... I use Salifert tests for all readings. <Good test kits> When I first noticed my alkalinity was low (2.51 meq/l), pH was 8.0, I started adding Kent's ProBuffer (Liquid form). I added the mfr's. recommended dose each day. In the following days, my pH have risen .1 each day. pH is now at 8.3. However, my alkalinity has remained below 3.0. It read 2.74 on the second day, then dropped to 2.51, then back up to 2.74. <Yes, this is a bit low...> My calcium has remained a steady 425 - 450. I use Kent's liquid calcium. I add it to my "NURCE" (automatic top off device). So I assume it adds a little calcium each time top off water is added to the tank. My water always tests at 425-450. <Some of this supplement is taking the alkalinity with it...> The only other additive I use is Kent's Tech-I Iodine, which I have since stopped using on the advice of my LPS.  <A serious hobbyist. You're now listening to Large Polyp Stony corals, Dr. Doofishle? For laughing out loud, I know you mean LFS> He (and I) have had a problem (small) with brown algae. He recommends Lugol's which I'll try in a week or so. Everything in my tank looks great! (so why am I complaining, right?). <Human nature, lack of real involvement in your work, easier than adventitious behavior... you got me> Thanks in advance for your help, Tony <Ooh, but there's more...> ALSO..... I just saw a new product, "Black Powder" in a magazine. Have you heard/seen anything on this product? <One of Weiss' re-inventions... don't know nada... or actually do know nothing about it. Bob Fenner, who wouldn't become obsessed over the alkalinity deficit (apparent in readings), but would still be aiming for the much cheaper (believe me before the supplement company's put a hit man on me) and safer, more stable calcium reactor route... And will refer you to the pH, alkalinity, biomineral sections in Baensch Marine Atlas v.1 as the best work up of these topics available in English.>

Re: Low Alkalinity Thank you once again. And YES, my LPS corals talk to me....don't they talk to everyone?????? (I'm ok....really) <Too much java juice for both of us today!> If I stopped adding the calcium altogether, could that solve the problem? Maybe use half of what I've been using? <Perhaps, and it's worth a try for a few weeks... Are you still tinkering with the home built calcium reactor idea? Back to the Lah bore ah torreee!> Hope all is well,  Tony <Yes, thanks. Bob Fenner>

Re: 75 Gallon Reef System I wanted to thank you for replying to my email, and also I did have a couple of other minor questions. One being that I have noticed that when I was using tap water for topping off my system, that the alkalinity was naturally higher than when I have used distilled water. <Sounds reasonable, doesn't it? In the short term, consider the simple addition of... baking soda! Yes, cheap sodium bicarbonate... to make up most all the alkalinity you and your corallines need.> My other question would be if you knew of any test kits that are more precise in there readings than just by matching color. I have trouble obtaining a good match by comparing colors obtained from readings and the colors on the scales. For instance Ph readings. I suppose the probes would be the only way to get a more accurate analysis of the true values. <There are amperometric, spectrophotometric et al. types of test gear that are definitely more precise and accurate... but not really justifiable expenses for aquarists use... Instead look into better Colorimetric assays... companies like Salifert, Hach... and you'll do fine. Believe me, these are what I use.> Thank You  Matt Smith >> <You're welcome my friend. Bob Fenner>

Baking Soda Hello, I had written you yesterday about some alkalinity problems, and you had suggested the use of baking soda. I was wondering if this is just a quick fix, or whether you can replace marine buffer with the baking soda on a weekly basis. I wasn't sure if baking soda also has a direct impact on Ph levels. Currently I am only using marine buffer. Although in the past I have supplemented with SeaChem's Reef Builder. I didn't know whether I could continue to use Marine Buffer and supplement that with baking soda, or use baking soda for a quick fix and then start adding reef builder again. Thank You  Matt Smith  >> A very large part of "marine buffers" is... um, simply baking soda... so, yes, this material can be used in the long term. By itself, sodium bicarbonate will not elevate pH much beyond 7.8... All the stated products are miscible. Bob Fenner