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FAQs on Marine pH, Alkalinity 5

Related Articles: pH, Alkalinity, Marine Alkalinity, Synthetic or Natural Seawater, Water Changes/Changing, Understanding Calcium & Alkalinity, The Use of Kalkwasser by Russell Schultz,

Related FAQs: Marine pH/ Alkalinity 1, Marine pH/ Alkalinity 2Marine pH/Alkalinity 3, Marine pH 4Marine pH 6 Marine pH 7, Marine pH 8, & FAQs on: The Science of Alkalinity, Importance, Measure, Sources, Use of Additives/BuffersTroubleshooting/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, & FAQs on: The Science of Calcium & Alkalinity, Importance, Measure, Sources, Use of AdditivesTroubleshooting/Fixing, Products,

pH Woes 3/20/04 Hello Adam or similar: <Hi Shannon.  Similar is out for the weekend, so Adam here<g>.> Per the long thread below, the results of the outdoors aerated pH test were very surprising. Before, in the tank, my meter registered about 8.05-8.14, from AM to PM, of course. Taking a glass of water outside and aerating it for about an hour, my meter said 8.53! <Wow!  Convincing evidence that you have CO2 accumulation.> Also, measuring a glass of tank water after TMC's Bio-Calcium was added showed the pH drop to 6.9 or so. This would make sense since it is essentially liberating CO2, which is acidic ... but I assume that if tank water was properly alkaline and the Bio-Calcium added at the recommended level, then the overall tank pH should stabilize back to where it was, given the buffering capacity of the water? <Hmmm.... Tricky to explain, but here it goes...  Your explanation is correct.  Adding bicarbonate raises alkalinity, but also initially lowers pH because of the CO2 that is liberated.  The pH will rise back to normal as CO2 dissipates to the atmosphere, not because of the pre-existing alkalinity.  Without getting into the complex chemistry...  CO2 rising and falling affects pH, but does NOT affect alkalinity.> One final note - my tap water is 8.3 straight from the faucet, and relatively hard to begin with ... perhaps this has something to do with my issues?  Thanks once more, SLC <If you are using your naturally hard tap water without RO and or DI filtration, there is no doubt that it will contribute to calcium and alkalinity.  In fact, many folks using hard tap water don't add any other calcium or alkalinity supplements.  Best Regards.  Adam>

Depressed pH? Hi-Thanks ahead of time for any help- My reef tank is been up for approx. 3-1/2 months, and I'm having a low ph-high alkalinity problem. 46 gallon bow reef tank 3-4 inch sand bed 50-55 lbs. live rock 4 powerheads Prizm skimmer 4 reef Chromis (biggest one about 4") 1 Yellow Candy Hogfish (approx 3") assorted snails Mushroom corals I was running 2 FilStar canister filters, and removed them per advice from some local reef folks. I had run them on my tank when it was fish only. Also, I just switched from Tropic Marin salt to the new Oceanic "natural" salt mix. <I am a Tropic Marin loyalist, so I have no experience with the Oceanic salt mix> It seems to be a fine mix-when I test the PH after mixing, I get a reading of 8.2 using a Sea Test kit. After doing a 20% water change last Sunday-I checked my PH Monday evening and got a reading of 8.0-8.1 When I test the alkalinity, I get a reading of 4.5 meq/l. The only additives I have been using are Coral Vital 3 times a week, and C-Balance from Two Little Fishies every day for a week. <I'm not a big fan of the Coral Vital, but the C-Balance is a fine product, IMO> On Tuesday, when checking my PH in the morning and evening my readings where 7.8-7.9. What could cause this problem? Could it have something to do with the removal of the canisters? I did use Chemi-pure in them. Is it possible I have a gas exchange problem? (i.e. poor aeration?) I would have thought a skimmer would facilitate the gas exchange-maybe mine is not big enough or efficient enough? Any advise and help you can provide is greatly appreciated. Keith <Well, Keith, I'm going to offer the most simple thought here, which you can easily test and verify as to whether or not it is correct. As you may recall, when lights are off, the system pH tends to decline. Conversely, after the lights have been on for some time, pH tends to be at its highest. Do test throughout the day to confirm this. On the other hand, depressed pH during "lights on" periods may be indicative of poor gas exchange (as you postulate), or perhaps an excess of dissolved organics in the water. Do a little testing of other basic water parameters to see what the story is. Good luck! Regards, Scott F>

pH troubles 12/30/03 Happy Holidays Anthony. <And to you!  Adam here by the way.> I am having the hardest time trying to bring my PH up. <Have you verified that your test kit is accurate or compared to another kit or meter?> I have a Kalk reactor as well as a calcium reactor. I have shut the calcium reactor off <Probably a wise choice until this is resolved.> My Ph every morning is at 7.7  and only gets up to 7.9-8.0 I've used a PH buffer a few times and it brings it up to about 8.2 but with in an hour it is back down to where it was.  The same happens with the Kalk it brings it up for a short time then it goes back down. <If your have verified the accuracy of your test kit, I would look to CO2 accumulation.  To test this possibility, take a sample of your water and test the pH.  Then, take a container full of aquarium water and aerate it with an airstone for at least 30 minutes.  If the pH is more than 0.1 different, you probably have CO2 accumulating in your tank.  This can be resolved by better surface agitation, allowing fresh air to reach your skimmer (if it is in the cabinet) or adding refugium or turf scrubber on a reverse daylight lighting schedule>. My Alk. is at 4 so it's not high or low. <Agreed as long as it's 4mEq not 4 dKH.> I've done two 35 gallon water changes in three weeks on a 135 tank with 70 gallons in the sump. 200 gallon system. <Water changes are always a good move, but will not have a significant effect if your test kit is bad or CO2 is accumulating.> Help me out with some suggestions please. <Please let us know if these suggestions solve your problem.  FWIW, CO2 accumulation is most common in very new "tight" houses where CO2 accumulates in the entire house.  You may have to aerate your sample out doors if this is the case.  Adam.> Chris

Calcium reactor, PH Controller, Measuring DKH Hi, I have had a salt water tank for 25 years, and have been successful with water changes and additives.  My tank is  300 gallons and  just purchased the Knop Calcium Reactor.  Could you give me ANY additional set up advice? <I'll do my best.> The information included with the unit was a bit sketchy. I understand the plumbing of the system, but have questions: 1.  The instructions say to measure the reactor output - to be 12-20 degrees DKH.  Is that a simple alkalinity test? <Yes.> Is there a way to convert results from a conventional kit to degrees? <Well, unless the 'conventional kit' contains a specific alkalinity test, no. One the other hand, the units of measure vary from kit to kit, and there is a way to calculate to German degrees of hardness [dKH].> I currently use Aquarium Systems FasTest saltwater aquarium test kit. <Not familiar enough to say if this kit has an alkalinity test.> 2.  I purchased a CO2 Azoo unit and a marine pinpoint ph controller.  Is this necessary to monitor PH swings, for example, at night. <I don't think the monitors are 'necessary' but certainly good to have around.> I read on your website that they are not being recommended.  If this is true, how are the pH swings handled? <Depends on whether or not the pH is actually swinging. A drop in pH overnight might be best dealt with by shutting off the CO2 with the lights.> 3.  During a water changes, the main pump that feeds the reactor will be shut off.  Can I leave the circulating pump on the Knop running? <Yes.> 4.  Once the Knop is set up and running - do I need to continue additives, such as iron, trace elements, iodine, etc.. <Iodine, yes... many others are provided by the dissolving reactor media. Do look at the bucket your reactor media came in - should be a list of what you can expect. Not sure if iron is on that list. Do feel that most trace elements are best supplemented by regular water changes.> Thank you for your assistance! <Cheers, J -- >

- Top Off and pH Struggles - Hi there, I got a couple questions here, I was wondering why I seem to understand from reading top off FAQs that it is wise to buffer RO water if used for evaporation top off for PH and KH however the water that leaves the tank is basically distilled water and has a TDS of 0 just like the RO water, so why is it necessary to add stuff to the water if essentially you are replacing the evaporated pure water with other pure water? <Because the pure water you are adding has a lower pH that what is required for balance in your tank. Just because the evaporating water leaves stuff behind doesn't make that same 'stuff' readily available to your top-off water.> I read somewhere that RO water was suppose to have a pH of 6.0, however if I test mine with my pinpoint pH monitor, it tests at 7.5, the pH monitor is calibrated, so it is accurate, and the RO unit is still running at its max efficiency, TDS tests at 0, so why do they say the pH of RO water is 6? <RO water should be very close to 7.0 which is neutral.> I'm also having problems with my Reef's pH, it is at 8.05 and it has been for a while, I think that it is because I had some homemade concrete stuff in the tank which screwed up the waters chemistry a bit, but I have removed all of it, and now have high Ca levels, like 650-700ppm which I think is giving my KH problems, anytime I add SeaChem's reef buffer to raise the KH to about 120ppm within a day or two its down to 70-80ppm, My magnesium tests around 1150ppm, is that too low with such high calcium? <I wouldn't worry about magnesium at this juncture.> I tried to add baking soda to raise the carbonates a bit, so I added 20 teaspoons, to the system which is about 260 gallons which raised the PH from 8.05 to 8.15 so I added another 20 teaspoons the next day thinking it would raise the PH to 8.3, but it went back down to 8.05, so what happened? <Something else in your tank is either depleting your buffers, or perhaps there's some of that concrete rock still in the tank somewhere... perhaps as small pieces.> Also now my KH tests at 200ppm after adding the baking soda. Any advice? <Yes... stick to just plain water changes for a month or two, and do buffer your top off water. Let the tank find a better chemical balance through the water changes. Don't any anything else for the moment - I think that is part of your problem. Cheers, J -- >

- Baking Soda - Depressed pH - Hello Crew! I have a question concerning the use of baking soda to boost pH (and alkalinity?) in a marine system. I have a new setup (450gal. total system vol.)  which I've been cycling for a month. I'm utilizing a new DSB of "dead" sand which has been inoculated from other aquariums and (temporarily) a couple very small pieces of live rock. I'm also running a 'fuge with a DSB and Chaetomorpha that was acquired from a mature system. System flow is in excess of 8000gph, temp is 79, and I'm running a EuroReef CS12-3 skimmer. I'm having trouble with the pH which is low and fluctuating between 7.9 and 8.0. Using SeaChem test kits; Ammonia, Nitrite, Nitrate are all undetectable, Alkalinity is 1.4 mEq and Calcium is 550 (I know this is telling me something but not sure what). I'm using RO/DI water and IO salt mixed to a specific gravity of 1.025. I've been trying to boost the pH and alkalinity with baking soda but notice that shortly after applying, the pH begins to FALL! (as much as a full tenth, measured with a PinPoint monitor) It will come back up within hours but doesn't get over 8.0. <What are you mixing the baking soda in? I'd use a cup of tank water and mix up a heavy dose - with a 450 gallon tank, you'd need boxes of baking soda to make any impact on the pH at all.> I've considered the two-part supplements but don't want to contribute any more to the already high calcium level. <And I wouldn't either at this point.> Any ideas, thoughts, suggestions on how to boost and maintain the pH? <I'd re-evaluate the pH issues when you get all your intended live rock in there. I think that will make a difference.> (total water change?) <Not yet.> Any notion why the pH falls with the addition of Sodium Bicarbonate? <Not sure... may be something in your methodology - are you adding this directly or in a mix with water?> Many Thanks.  Eric <Cheers, J -- >

pH, marine, reactor First of all I would like to thank you for answering a question I had earlier on a elegance coral, I do have a question to ask about pH. I have CR-1 CO2 unit running on my 90 reef dKH is 12.2 <Am I to understand this is the Reef Creations calcium reactor, CR-1? You realize that if you were running straight CO2 into your tank without a calcium reactor, this would be the source of your problems.> The problem I have is with the pH not able to climb above 8.0, I do buffer my top off water to 8.2 and my salt mix is instant ocean, ph does drop at night to 7.8 - 7.9 up only during the day to 8.0 I do monitor with Milwaukee ph smart monitor. Any ideas why I can not bump up ph higher than 8.0, some times this even falls to 7.9 during day light hours also. Metal halides 2/ 175 10,000k 2/110 actinics halides on for 10 hours actinics on for 13 to 14 hours, salinity 1.28, calcium at 430. Your thoughts will be grateful. <Hmm... no information about the pH of the effluent coming out of your reactor... please let me know, I might be able to make a better guess as to what's going on.> Thanks Brian <Cheers, J -- >

- Low pH, Reactor Adjustment - Yes this is a Reef Creation reactor, my effluent is at a pH of 6.7 and the bubble count is 1 burst every 3 seconds my effluent is at a steady drip not a running flow but to fast to actually count the drips. <You could be ending up with excess CO2 in your water. Can be tested by taking a water sample, and taking a pH reading of it. Then aerate the sample for a couple of hours and the test the pH again. If the pH rises significantly, you have issues with excess CO2. For now, I'd shut off the CO2 solenoid with the lights on the tank. Prevent the reactor from pulling down the pH any more than necessary over night. Cheers, J -- >

Declining pH... I'm currently about 10 days into a new 38g salt tank. I'm using half RO and half DI water with 3" substrate, 2 lbs LR, and 1 hearty Domino Damsel. My readings are off the chart in all Categories.   < I'm assuming that you're referring to ammonia and nitrite. If so, sounds like things are cycling normally. Too bad the damsel can't be relocated elsewhere...> My PH is 7.8. Why? <The pH tends to decline as a result of organic acids and/or CO2 in the water, among other things. In a new tank with lots of nutrients, this is quite common. When things stabilize after cycling is completed, I'm sure that the pH will level off with good husbandry. Keep in mind that the pH also varies from day to night, so test at different times of the day (lights on and off). It started at 8.2 like textbook. Is this part of the cycling? I added the baking soda as recommended other places. The pH came up for 2-3 days and has settled back at 7.8. <Again, I think it's part of the cycling process...Keep monitoring and recording results...It should stabilize...> I'm going to add 30# LR tomorrow. All inputs greatly appreciated. Rob <Well, Rob- my theory is just one of the possibilities, but I'd consider it a good one for now. There are a lot of other factors that can result in declining pH, but given your tanks' status (new), I'm thinking that this may be a good one...Do also consider things like the source water pH and alkalinity, etc. Regards, Scott F>

-Top off water driving pH down?- Hi, In a recent water check I was told that my top off water is low in pH. It is resin filtered from a well. I have to add a lot because of evaporation, and it was suggested that I might be driving the pH down with the top offs. My current PH is about 8.0 - 8.1, I hit it with buffer twice and haven't been able to get it to 8.2. <What's your carbonate hardness at? Also, having a pH from 8.0 to 8.1 isn't the end of the world and is perfectly acceptable if your carbonate hardness is in the correct range.> How can I adjust the pH in the top off water, and what should it be? <That would depend. If the resin that filters the well water takes out only a few things and leaves most of the dissolved stuff intact, I would suspect that it would be around neutral. If you use deionized water, the pH could be any given value, and would change instantaneously should any buffers be added. I prefer to add straight RO/DI water and maintain the KH via calcium and alkalinity additives.> I used buffer in the top off water, but it left a lot of white powder residue, but it did adjust it to about 8.0 or so. <No worries. Check the KH of your aquarium, if it's anywhere between 9-12, 8.0-8.1 is the best your going to do for pH if the problem isn't excess dissolved CO2. If your KH is low, add some buffer to raise it to the appropriate level> I heard you could use just baking Soda. <That's true, but check your KH first. Good luck! -Kevin> Thank You, Randy

- pH Level of Top Off Water in a Marine Aquarium - Hi, I am probably not going to be talking to the same person, but I wanted to put in a small follow up. <You win the prize, this is not the same person - JasonC here rather than Kevin.> I starting running an airstone in my water bucket and the pH change in 12 or so hours was major. It went from below the scale to around 8.0. <Interesting.> The DI kit that I bought that connects to the tap went dark all the way to about 1/2 inch from the top the first time I used it. <Mmm... double check you are connected to the proper end of that cartridge.> I thought this was strange, but at the same time I doubted that the well water could possibly be that bad. <You never know.> It has no odor and I have seen bad well water. <Bad well water can be odorless.> I checked the filter's output for nitrates since that was the reason I bought it in the first place (I was getting around 40 out of the tap). I decided that the color change was useless since it went that far on the first few gallons. I am seriously considering an R/O system, any suggestions on the best one for under $200? <Consider a bare-bones RO unit... that should get you in under that door.> I am not rolling in money at the moment. Oh, also....What is the best dKH test kit for general purposes (your view), <Salifert, SeaTest, Sera.> Mine is apparently junk and claims to an ALK test. <Well, from your previous email you indicated that your test only measured low/medium/high - that's really the largest problem with your current test. Rather, a test with a numerical result on a standard scale like dKH, mEq/L, or ppm.> It isn't much help. <It is of some help but you can do better.> Thanks again Randy <Cheers, J -- >

- Low pH Problems - Hi I've recently (5 weeks) set up a marine aquarium - 50 gallons (2 ft cube - so limited water surface to volume).  I used half tap water and half RO water (as I'd been told local tap water was alright by other fish keepers).  Since which I've done 15% water changes 3 times with RO water.  I have a  10 gallon sump with a trickle filter which turns the tank over about 6-8 times per hour, as well as 2 powerheads which between them turn it over about 12-15 times. All readings appeared to be fine, so I added 2 hermit crabs, 2 damsels and 2 turbo snails about 2 weeks ago. (they are all still fine)  I didn't have a very good ph test kit  so I took the water into my LFS for testing - pH was between 7.7 and 8.0 (closer to 7.7). I bought a decent test kit (Salifert) and the buffer recommended by the shop - a liquid buffer (Kent freshwater, the LFS said it would do the job as he was out of the marine stuff - it says on the bottle for marines also). <I hate to rain on your LFS' parade, but you can use baking soda as a buffer just as easily - in fact, I'm on my way to the store to pick some up.> He also tested the hardness as I didn't have a hardness test kit (the LFS hasn't had any in for weeks - prob.s with order, he only had his own) and said that was fine. Initially the water seemed to come up to 7.9/8.0 but I'm not sure if it was just wishful thinking on my part. The buffer had no effect so 3 days ago I went in again. The LFS gave me (for free this time) 2 table spoons of some white powder buffer (looks like fine sugar) and said I only needed a quarter teaspoon. He said it was really strong and should do the job.  I've put in a quarter teaspoon 3 times! (waiting between 12-24 hours each time)  This still seems to have little affect.  I know the pH test works as I've tried it on other water - both acidic and alkaline. In the meantime I've had an order (which I placed 2 weeks ago - thinking everything would be sorted) for 6 hermit crabs and 12 turbo snails arrive mail order.  I put them in and after 2 days they now seem fine - moving about, even though the pH is still low. So in summary - pH 7.8 -7.9 Hardness fine <What is fine? Do you have a number?> Lots of water circulation - I think (I was told trickle filter put lots of air into the water) All livestock including inverts fine Calcium fine (tested for that) Tried 2 different buffers <Again, just plain baking soda should do the trick - about a teaspoon per 20 gallons, dissolved in water - per week.> I am getting a little impatient as I've been waiting a number of years to get a marine aquarium, the nitrate, nitrite, ammonia etc are all good. (tiny readings one of them - not ammonia - but LFS says not to worry) Do the buffers actually take 24 hours to work? <They do take time but not this much.> Or is it just that the pH should not be raised by too much over 24 hours? <That as well.> I do have a protein skimmer - with a venturi which looks like it's doing the right things, but I have no scum coming off the water. <No appreciative bioload at this point is the most likely cause.> Obviously I only have 2 small fish, and there is a few kilos of live rock and lots of filtration. I have put in Rowaphos to deal with the brown/black algae (diatoms I think) which covered everything - it seems to have done the trick.  It's in a 204 Fluval canister filter which is attached to the sump. <Didn't see a mention of any other calcium-based material - crushed coral substrate... etc. With only a few kilos of live rock in there, you don't have much of a foundation for good alkalinity, which is the support for a stable pH. Do try the baking soda, and likewise add that to your RO water that you use to make new saltwater.> regards Meirion <Cheers, J -- >

- Low pH Problems, Follow-up - Hi I have also got 2 inches of aragonite sand - lots of Ocean/Texas Holey rock and lava rock. <Interesting... is quite possible the lava rock is what's pulling your pH down - is not really a suitable marine decor.> The magnesium level is low and according to the LFS that will keep the calcium and pH down - it reads as 1000 ppm. <I don't agree with that.> So I'm adding TechM made by Kent marine to raise the magnesium - could this be it or am I is the wool being pulled over my eyes? <I think the store is trying to sell you supplements - you should get all the magnesium you need from regular water changes with a reputable salt.> I will also try baking soda as suggested. <And do consider losing the lava rock.> regards Meirion <Cheers, J -- >

- Low pH Problems, More Follow-up - Hi <Hello.> I was wrong to call the rock, lava rock - it is in fact 'Arago-rock'. It is a very light weight dark coloured 'rock' that has a bubbled texture. <Ah, ok then.> Apparently it's actually man-made - it is inert and lots of people use it in their marine aquariums over here, (UK) it's sold in every specialist marine aquarium shop I've been in to as being a good base rock. <Fair enough.> However I think I may have solved the problem - the light that is on the sump broke a few weeks ago and as I haven't actually got anything cultivated in the area that is going to be the refugium yet, (just a trickle filter with bio-balls.) I hadn't bothered to replace it.  The water in the aquarium now reads about 8.0 whilst the water in the 'refugium/sump' reads closer to 7.7.  I read that light can affect the pH. <I've never heard of this.> Is this right - or am I going mad? <I think you are grasping at straws... you need to look for other more realistic sources of the low pH - I'd be investigating the freshwater you use to make your saltwater as well as perhaps other decor that might be dragging your pH down.> I do need to replace the light starter unit anyway - so I'll soon find out if this helps. Thanks for all your help - I was always rubbish at Science at school and this is stretching my knowledge to the limit. Thanks Meirion <Cheers, J -- >

Rock solid tap water and a low pH Greetings and salutations fish people, I have been battling a recent bout of lower than desired pH, and questionable tap water. The setup: 180 gal FOWLR~130lbs of live rock sand bed ranging from 0" deep to 5" deep (depth is decided by my fishy) wet/dry filter (still with bio balls) DIY skimmer which seems to work reasonably well: usually about 1cup of decent skimmate every 2-3 days~3250 gph total circulation (love those new Tunze streams) The fishies: 3 damsels @ about 1.5" each 1 adult skunk cleaner shrimp and 1 Gymnothorax fimbriatus @ about 35" named "Corporal Clegg". Had this little guy for about 7 years now. It is my hope to someday soon set up a refugium to get the Caulerpa out of the main tank and to also house some pulsing xenia.... maybe some xenia in the main display too :D.  From reading through the FAQs, I understand that the Xenia are pretty demanding on high pH: so begins my battle with trying to raise my pH The temp is kept at a stable 82F, attempting any lower and I start to see temperature swings of more than a couple of degrees. I have seen the pH in the display range from 7.9-8.1 at various times of the day, but the majority of the time it is a steady 8.0. This is measured with a digital pH pen from Hanna Inst. that I calibrate frequently. Other pertinent measurements in the tank - 11dKh Alk and 400ppm calcium.  I do not supplement w/ any calcium anymore as I currently have no calcium hungry critters.  In the past I have tried to drip Kalk at night to try and raise pH, but had to stop because my source water had such high calcium numbers to begin with. I've tried opening windows in the house to let more fresh air in, but have seen no affect on the pH.... not a surprise since my house is pretty drafty in the first place. So now I start looking at my source water trying to find out why water why my pH is still low: I follow your instructions on treating tap water: I let it sit for 3-4 days before use, running it through a poly-filter for at least 2 of those days. Then mix salt and aerate for about 3hours with the help of a maxi jet venturi before use. Before mixing the salt (Instant Ocean) today, I measured the pH to be at 8.3 already.  After mixing the salt and aerating the water, it was at 7.8!!  WTF??!!! So I test Alk and Ca.  Ca was at 400ppm which is a bit lower than it has been in the past.  Alk was off the chart of the Salifert test!! I had to refill  the 1ml syringe to get the test to change colors - came out to be about 18.4dKh.  How is this possible? Especially when seeing a low pH?  I have tested twice to make sure I didn't screw up the test... same results.  Is there something else I am missing out on?  Given that this would be a 40gal water change, do you think it would be safe to do a water change with this water?  I am completely baffled here.  If these numbers are accurate, this seems like a huge swing in the hardness of the water in a short period of time (I test the source about every 3 mo.s) I will need to wait for a couple more paychecks before I can buy a dedicated high output RO system for the water changes, but what can I do in the mean time? Thank you in advance for your help. Mark < well mark you have done everything possible. I can't believe your alk is that high and ph that low. Try looking on the test kit and see if the expiration date is past due. I would use a Salifert ph test kit to verify your meter .I have found that meters can give false readings. Mike H>

pH shock symptoms Mr. Fenner, <J> Can you list for me the possible symptoms of pH shock in fish? I have one purple Firefish who, for 2 days now, spends all its time resting on the substrate, and seems to be bumping, head first, into the rocks quite frequently. He is able to remain upright and swim somewhat, but mostly remains perched on the bottom. I also lost my flame angel 3 days ago quite suddenly (I had only had it for about one month). I have had the Firefish since the beginning, around February 2003. The other fish (2 true percula, another purple Firefish, 7 blue-green Chromis, orange-spotted goby, 2 cleaner shrimp, 2 peppermint shrimp, hermit crabs and snails) all seem fine. My tank is 65 gallons, with a wet-dry filter and protein skimmer. I also have about 75 lbs. of live rock and one purple-tip anemone. Yesterday I measured the water quality: pH 8.0-8.1, nitrate 10, ammonia 0.0, nitrite <2, specific gravity 1.0235, and the temperature holds between 76-80*F . I buffered the water to 8.2 yesterday, and plan to bring it to 8.3 over the next few days. I will admit I had not been keeping as close an eye on the water quality as I should have been. Any advice you have would be greatly appreciated. <Something, though I doubt it is pH related seems awry in your system... based on your account of livestock loss. pH instability is often evidenced by aquarists in terms of behavioral anomalies... slow or rapid breathing, hiding, resting/listless posturing... You should have no discernible nitrite... has this tank been up long? What filtration, aeration, circulation do you have? Any live rock use? I would not be overly concerned/focused on buffering your pH here... 8.1 is fine... Bob Fenner> Thank you, J. Laurion P.S. "The Conscientious Marine Aquarist" has been a huge help! Great book for a beginner!! <Thank you for your kind words>

- Live Rock Problem -  I have just had a big problem with my live rock. I noticed that my tank had a slight odor to it. <Sounds to me like the rock was not fully cured.> I tested the water and everything was 0 but the pH was about 8.0. I did about a 15% water change and the next couple of days the tank looked great. <But what was the pH?> Then I noticed that crabs and star fish were not active and the water was slightly cloudy. As the week went on the water became cloudier and the fish started looking slow. I tested the water and everything was 0 but the pH had fallen to 7.4. I added a buffer and within minutes I noticed everything being more active. The next day I tested the water again and the pH had fallen back to 7.4. I added the buffer again and retested the water. The pH was back up to 8.3. A star fish was dead along with most of the crabs, a blue tang, and a bicolor angel. <Hmm... probably killed by the pH swings. For each tenth of a point, you either halve or double whatever value you are looking at. pH 8.1 is twice as acidic or half as base as pH 8.2. Any time you attempt to change pH, you shouldn't move more than a tenth of a point in a day, even less if you can do it.> I took out the live rock because there looked like a white film was over it. It was then that I noticed the rock was bad. The bottom of the rocks were black and smelled so bad. I placed them into five gallon buckets. The next day algae covered rock that once was purple and green was now 100% black. Do you have any idea what happen? <It seems to me that perhaps your rock is not fully cured.> The only thing I can think of is that the bottom of the rocks were not getting any O2 so it started to die and break down. The smell was like sulfur and that might be why the pH was dropping. <The die-off on the live rock was probably what was pushing the pH lower.> So now that the rock is black is there any coming back for it, or is it time to bleach it? <Give it two to three weeks in a tank or Rubbermaid bin of its own, with proper circulation and protein skimming. Scrub off the dead algae. The rock will be worth using by then. You might want to peruse this FAQ and the FAQs beyond as the process has been detailed there: http://www.wetwebmedia.com/lrcurefaqs.htm > How can I stop this from every happening again? <Cure the rock first, then add other life.> Even the live sand smelled bad. Could that have been a problem caused by the rock or maybe the other way around. I am so lost. Had everything perfect for about 4 months and now this happens. <Hmm... four months... well, perhaps the rock was cured or partially-cured, with much algae and other life that had not been cleaned off. Because you don't detail much else about your system, I can only guess that your problem was related to a lack of circulation... this would create these dead zones which you describe. Very likely it was a combination of these factors that brought down the house, so to speak.> Very quick too. Well, thank you for your help.  <Cheers, J -- > 

Low pH shock? Hi guys, <cheers from across the pond> It's been a while since I have had to write to you (which is a good thing -no offence!) <understood <G>> During the recent heat wave we had over here in the UK, many of our corals in our reef tank bleached.  (Huge investment in a tank cooler for next year!)   <Arghhh! So sorry to hear it. Only so much that evaporative cooling can do, indeed (fans)> Happily, some of them are recovering now and are getting their algae back.   <slowly but surely they will recover> Anyway, we have slowly started to replace the corals that didn't make it.  Yesterday, my hubby inadvertently tipped a lot of "Amquel" into the tank - I am not sure how much. The tank pH was already slightly low and he was going to add buffer etc afterwards.  The corals shriveled up and have not come out to play since.  I logged onto the Amquel site and read that you should exercise caution when adding to a tank of low buffer reserve.   <risk of buffer precipitation I presume> I assume the corals are suffering from mega pH shock.   <hmmm... perhaps. Overall irritation> If we raise the pH slowly over the next few days will they recover or have we lost them all (again)?  The fish seem to be fine. Thanks very much. Lesley <not lost again... and please do not add more chemicals (pH adjuster) to compensate for an overdose of another chemical. Instead, remember the admonition: "Dilution is the Solution to Pollution". What you need here is simply a large water change or two in the next week to dilute the problem, raise pH, and bring all back to par. 30-50% each time with well-aerated/adjusted water. No worries! Anthony>

New salt water-ph adjustments 10/18/03 hello Anthony, WWM Crew, hope all is swell out there.   <better than swell... we are teetering on ducky. Thanks for asking!> I've been having a problem for a while now with making new saltwater.  I've read everything on the site and follow the whole make-up to the tee.  I've used a lot of different salt, but I went back to IO this time.  Here what I do, did, I fill up a 40 gal. trash can with RO/DI water, aerate using a mag-3 for over night, next I add about 2 tsps. of Seachem marine buffer, then I let that go overnight.  I do test the alk and that is usually around 4dkh after that and the ph on my meter reads about 8.1 .   <all good... although you don't need to let the ALK get that high... lower(3ish) is fine/safer> I then add the IO salt and circulate overnight again, then I test the specific gravity , which is on the mark, the alk is like a 16, the ph is 8.0.   <lets be clear here... are you testing ALK in dKH or meq/l?> That is the problem I've always run into when I mix my salt.  What I did this time was add some more RO water to dilute the high alk (about 4 gallons) and that brought the ph up to 8.3, but then the SG was off so I then added more salt and the same thing with the ph dropping happened again, and I find myself adding the Reef buffer to bring up the ph and not so much the alk.  This is an all to common problem I have and maybe you guys can help make it easier for me .  thanks <if ALK is being measured in meq/l here... you are adding too much buffer my friend. If dKH, then I am not sure of the prob, unless your RO is weak and admitting too much mineral content (do test some raw RO water). Kindly, Anthony>

Re: New salt water-ph 10/18/03 thanks, I'm measuring my alk in dKH , you say to measure my RO water?  what should I be testing it for?   <we are looking to see how much if any hardness is in the finished RO water (assumedly low/zero... but we need to confirm). If your RO water is high quality, and the ALK level is still high after salting, then there is clearly an error with your test kit (misreading). From any unsupplemented off the shelf sea salt, you should not be getting a real/actual sky high ALK> If its the alk, I have run a test on it before and with 1 or 2 drops of the aquarium systems alk test it shows the change, so I do believe its buffer is almost completely out.   <excellent. Then do try simply aerating your RO, not buffering, then salting. Your ALK after that should be low then since sea salts presume you have some hardness to the water (this is another way to see if your test kit is high/inaccurate)> what else could I be doing?  I tested this morning and ph was at 8.13.  Can I use this water for a water change, or what should I do?  I hate to waste that much water and salt..  thanks   <I do believe the water is fine... just less need for buffer in the display after such a water change for longer between exchanges. Anthony>

- Hair Algae and pH Low - Hi Guys, I've been a reader of your excellent site for some time now. Here's my situation. I have a 55 gal. tank with 2 inches of live sand, 50 lbs of live rock. My circulation and filtration is all hang off the back. I have two whisper filters and a bio pack II protein skimmer. The tank has been up for over a year now. Initially, the lighting was poor with two 18 inch fluorescent bulbs. I replaced them with two 55w compact fluorescent combo bulbs. Still not enough light for corals. I want to go in that direction. I am planning on adding a couple of 175W 10K MH bulbs. But in the meantime, I have a hair algae problem. Also, even though I drip Kalkwasser and add Kent super buffer, I can't get the pH higher than 8.0 and the KH is 13. I added a Xenia about a month ago and with the PH at 8.0, I'm surprised it is still surviving, it certainly doesn't pulse at this time.. So here are my questions: What can I do to get the pH moving north? The super buffer says it's goal is to get the PH between 8.0 and 8.3 but from what I read on your site the Xenia like pH in the 8.6 range. Can I add baking soda in small amounts? <Yes.> What do you suggest? <Perhaps try buffering your water change water before you add salts... try to make sure all new water going in has good alkalinity. Would be a good place to start.> On the hair algae problem and I've been taking the live rock out and using a toothbrush to remove the hair algae but it keeps coming back. What can I do to starve the algae out? <You might want to run a phosphate test to see what your levels are - this acts as a ready source of plant food for algae and often becomes a problem from overfeeding. Another thing you can do is increase the circulation inside the tank by the addition of a couple of powerheads.> Will the addition of two 175 MH bulbs increase it's growth or help to kill it off? <It will most likely increase the growth.> I've  got one of those cleaner gang packages from Marine Depot so I have many snails, crabs, etc. They don't feast on the hair algae, so I'm at a loss as to how to get rid of that problem. I have a few small fish in the tank as well. The ammonia and nitrate levels are zero. Thanks. <Cheers, J -- >

- Strange Losses, Follow-up - Sorry about the wrong info on the ph, I was at work and working off memory of color and thought the purplish/brown test color was 7.8, it is actually 8.2... <Ah, ok...> but sometimes does vary to the 7.8. <That's not ok - it really shouldn't vary at all, or even much. Going down to 8.0 is too low and 7.8 is just bad news. I'll stick with my original spiel and suggest that your problem is the fluctuation. If you think about it for a bit, the oceans cover over 2/3 of our planet - things don't change there very often, if at all. Any fish tank, even the largest ones are smaller than a grain of sand in comparison to these oceans. The fish from these oceans are not accustomed to changes in their environment. Your goal should be to have a system that is as stable as possible - free from wild fluctuations in pH, temperature, etc... trying to duplicate their natural environment. Anything less will lead to excessive stress and big problems.> Again, I'd look to stabilizing this before you add any additional fish.> It is usually 8.2 though. thanks for the info <Cheers, J -- >

- Adding Pure Oxygen - Hello again there fellers, all of your help has been truly welcome.  I have a question concerning the addition of oxygen to my tank by way of bubble counter into my skimmer to combat the CO2 build up that has been accumulating in my house since it is cold out and I have to keep my house closed.  My pH drops when I have my house closed because of the build up of CO2 and have tested for this specifically in the past.  Don't have the issue in the summer because my windows are usually open a lot.  Would it be unwise to add oxygen to my tank via a bubble counter hooked up to my skimmer for the added oxygen? <Hmm... I'd say adding pure oxygen could cause some problems - oxygen toxicity being my primary concern but also excess oxygen outside of the system. Chances are pretty good that any oxygen you add will bubble to the top of the tank without reacting with anything and instead going into the atmosphere. You're better off just using a bubble wand and an air pump and relying on regular air. The bubble action should help drive off some of the excess CO2. You might also want to develop an algae-based refugium under 24 hour lighting where you would have willing consumers of CO2.> Maybe one bubble per 5 or 10 seconds or more or less?  What would be the negatives if any? <Increased ability to combust and/or oxidize items in your home. But more so, that while good-intentioned, this will not produce the affect you desire.> Would this not increase the oxygen and counter the CO2 build up? <Sounds good in some ways, but the air we breathe is not pure oxygen - it's about 21% oxygen. Adding pure O2 is asking for trouble. Likewise, O2 is chemically very stable, so it's not very likely that it would react with anything in the tank, meaning you would still have roughly the same amount of CO2 in your system.> I have access to an Oxygen tank and would need to buy a solenoid and bubble counter.  I have quite enough water flow in my tank and am using a Euro Reef CS6-1.  It's a 180 gallon.  It pulls out massive amounts of gunk and have to clean it at least 1-2 times per week.  I have a lot of SPS along with a few LPS and softies.  Yes, I agree big load but am concerned with keeping the pH up.  I add Kalk daily at night which boosts the pH up from 8.06 to 8.3 at the most.  Also have a calcium reactor that does quite well at keeping the calcium and alk in tune.  Any thoughts on the cautious addition of oxygen? <You got 'em.> Thanks again, Jeff <Cheers, J -- >

pH shock from Kalkwasser 9/29/03 I have a 59 gal. coral reef aquarium.  I had ten corals and nine fish.  I have had the set up for about three months and it was time for a water change.  I mixed up my water with the salt and primer, but I added Kalkwasser.  Since I am a beginner, I am also stupid.  I did not read the entire directions and I added all of the new water at once instead of gradually.  Well, all of my fish have died but two and most of my corals have died.  Is there anyway to counteract the Kalkwasser as I am sure this is what I did wrong?  Do I need to make another water change?  I am very depressed about this since I lost about $500 worth of stock.  Thanks. Terry <very sorry to hear of it my friend. If there was no precipitous reaction, it sounds like you simply pH shocked the system. The best solution is dilution.  A couple of large water changes and you will be back on your way. Do get yourself a couple of good reef references too. Eric Borneman's aquarium corals is an excellent photo reference... and my Book of Coral Propagation has most of the first 200 pages dedicated to no-nonsense plain language reef husbandry. Wishing you the best of luck! Anthony Calfo>

- Clarification on pH Shock - Hi guys! <Hello.> I've read so much of your site that if I was making minimum wage reading it I'd be rich. I also set up my tank using CMA as the supplementary guide along w/ WWM. Indispensable both, & I could not have done my setup without it. My question is, I cannot find a single thing anywhere about what to DO about pH shock. I see it mentioned occasionally & a few dire hints about it, but not what it exactly is, is caused by, or most important, how to TREAT it. <Hmm... well, without going any further, I can answer those questions - pH shock is simply a drastic change in water conditions [specifically pH] encountered by some living organism to whom the pH is important. So... let's talk about marine fish who are used to a range of pH 8.2 to 8.4. Because pH is a logarithmic scale a change from 7.0 to 8.0 is in fact a change of 10 times greater - moving in tenths of points [0.1 to 0.2] is a doubling of the factor, as moving down in tenths of points [0.2 to 0.1] is a halving of the acid/base quality of the water. Because the ocean is so large, these numbers rarely if ever change so marine fish aren't really equipped to deal with sudden, and potentially large changes in pH. If a fish has been in a bag for shipping for a day or so, the pH of its water typically drops into the high sevens... if you were to move the same fish immediately into traditional holding water of pH 8.2, it would experience pH shock. And no, there's nothing one can 'do' to remedy the problem. There are plenty of things one can do to avoid it. The pH shock becomes a source of stress which will go onto the existing pile of stress - depending on the individual, this can either tip the balance in the wrong direction or the fish will make it through to the other side. It depends a lot on how much the fish has been through up and to that point.> I had a Volitans Lionfish who died just now & I'm 99% sure it's due to pH shock. I say this because he was fine for a week or so in his tank. Water conditions were fine (obsessively measured w/ Salifert tests for pH, ammonia, nitrites & nitrates every day or two). Water had been running a bit hot (sometimes climbing to 83.5 or so but never more than a degree a day change). The temperature thing has been remedied (not enough evaporation/eel-proofed tight glass top). I got a Foxface Rabbitfish & decided as per CMA to dip him prior to introduction. I used RO water from LFS I had matched to the tank's temp, w/ some "AP Quick Cure" (Formalin/Malachite Green dip mix) & buffered the water with Kent Marine Superbuffer dKH (which per the label is for raising & buffering pH & building KH). I mixed this up & let it sit a while then dipped the Foxface, who had been in panic coloration on his way home from the store. He went limp & drifted almost instantly. <Many fish do this in the bath... is sometimes more stressful for the person doing the dipping work than it is for the fish - think you could have skipped the quick cure though - you are not exposing them to the treatment long enough for it to do any good. Better to just run the fish through a pH-adjusted freshwater dip - perhaps with methylene blue if you'd like, but not necessary.> I spooked & netted him out & put him in the tank after MAYBE 30 seconds (he'd already been slow-drip acclimated). I had planned to dip the Lion as well since he had not been when he was introduced a week & a half ago (my only other fish) & went over the instructions for freshwater dips as per CMA. I convinced myself that it was normal for the fish to freak out a bit & that I had to exercise some "tough love" & that he had to stay in there for the 2-10 minutes. I nabbed him & put him in the dip. He sat on the bottom lazily & was breathing regularly. I set a timer for 2 minutes & watched him the whole time. Put him back in the tank & he seemed ok. Well, he spent the entire afternoon & night on the sand bed, breathing seemingly regularly but listless (which is pretty usual for him anyway minus the being on the sand part). I figured he was aggravated & stressed but nothing unexpected from being dipped in freshwater, etc.. The next afternoon he had not improved, having merely moved to different positions on the bottom two or three times. When I came back an hour later & checked on them, the Foxface seems a-ok, swimming around, nibbling algae, back to his normal coloration. The Lion was floating nose-down dead along the bottom & his fins had already started fraying off! <I'm sorry to hear of this loss.> Sorry for the long email but I'm upset & trying to provide all possible pertinent detail. I can only assume the Kent buffer did not work (or have time to work?) or at least that was my first instinct. <Takes time to work - I usually prepare my freshwater dips before I head to the store so that everything has evened out by the time I make it home with a bag in my hand.> I looked on various forums & came up with the info that "people assume buffering the water then dipping is ok...it's not". Was it pH shock that killed the Lion, & if so how could I have saved him, if at all? <Hard to say for certain - it could have also been the formalin in the quick cure you put in the bath. This is actually really 'bad' [toxic] stuff and I've had similar results as you - dip one fish and it does fine, dip the next fish and it turns stiff almost instantly.> I feel like I killed a healthy fish through sheer gross idiocy & messing with what would have been ok had I left it alone. <Maybe so, maybe not... there is an old(?) axiom in the trade that if the fish didn't make it through the dip, it wasn't going to make it anyway. I'm sure this is no consolation to you, but it's quite possible that this fish was compromised long before you got a hold of it. Considering the Rabbitfish is still around - and I'd consider it a less hardy fish than a lionfish - I'd say something was already brewing with the lionfish and the dip just accelerated the process.> I now see that a lot of people (mainly reefers?) seem to revile freshwater dips period. <Not me... I think they are quite useful.> I guess my questions is threefold: was it the dip, was it pH shock, & how should pH shock be treated? <Again, hard to be certain it was any of these, and pH shock can only be avoided, not treated but also is rarely the single cause of mortality, but one factor among many that bring around the end of the fish.> I think this info would aid some people greatly & at the least it should be added to the database at WWM to make sure people are aware of this. <Well, we do try to get the word out, and most certainly this will go into the collection.> I consider myself very well informed & research everything before doing it & still I fell face first onto this one somehow. ;( <Don't be too hard on yourself. Cheers, J -- >

pH balance Hi Bob, Do you know of anyway to maintain PH at 8.0 to 8.4 for marine fish? Currently I'm using Sodium Bicarbonate and Sodium Carbonate to buffer my holding's PH. Is this a good way or there's another alternative better way? <This is the best way chemically to do this... either yourself or buying a commercial product made of the same (plus borate and possibly another ingredient or two). Are you measuring alkalinity? Are you able to run the water (natural or synthetic) over a carbonate based substrate? Protein skimming, other filtration use could help reserve your alkaline reserve as well. Bob Fenner> Pls advise. Thanks Cheers, Charles

Alk and pH askew 9/13/03 Hello, I am still trying to find a cure for my rapidly declining pH at night even after I add Kalkwasser.   <several possibilities... if you have a very heavy/large population of corals and/or macroalgae... it could be respiration from photosynthesis (heavy activity)> I am running a Knop C calcium reactor with Carib Sea ARM media on my 180 gallon acrylic tank w/60 gallon acrylic underneath.  Both of which house numerous stony corals (SPS and LPS) as well as a few softies here and there (leathers and mushrooms).  I have had the tank running quite successfully for about 16 years with lots of propagated stonies as well as LPS over the last two years.   <ahhh... could be the case here - a very mature and well-stocked/overstocked display> No allelopathy noticeable between species.   <not correct, mate... there is allelopathy, but it has simply been managed well by your husbandry no doubt. And too... surely some species over the years have waned or died for unknown reasons while others flourished?> At last check (last night) my tank pH was 7.99 with a Pinpoint pH monitor( calibrated against Fastest pH test kit and Hanna handheld pH/temp monitor).  This is after two days of not adding Kalk.  pH usually runs between 8.1 and 8.3 with the addition of the Kalk at night.  Low of 8.1 in the morning and raises up to 8.21 on its own by lights out.  Both the Hanna and the Pinpoint have been calibrated with 7.0 and 4.0 calibration fluids and are within .08 ppm of each other.  Tank kH was 5 and 4.9 (TOO LOW) respectively with Tetra test kH kit and also Sea Test alkalinity test kit. Tank calcium is 425ppm with Salifert test kit.  Salinity-1.024 and does not fluctuate because of switch/pump operated top off system that I use daily to top off with RO/DI water.  Calcium Reactor effluent parameters are: kH-28 w/Tetra test kit pH-6.68 with Hanna handheld pH/Temp tester calcium-600 w/ Salifert kit ( I assume it is this because I had to use one full syringe and then fill another up and drip in another .2 from the 2nd syringe).  The directions say to take the total and multiply by 500 and I come up with 600.  I am wondering why the tank kH would only be 5 when the effluent kH is 28?   <if the Ca has strayed too high ('tis on the higher end over 425ppm)> Does this have to do with the fact that I dose my Kalk according to the slurry method that Mr. Calfo instructs in his wonderful book Coral Propagation? <sort of... perhaps. That is to say, Kalk added by any method too fast or to excess can suppress KH> Will dosing Kalk in this manner keep kH down and necessitate the addition of Reef Builder that I use by Seachem?   <more of a simple matter of backing off the Kalk and/or calcium reactor slightly. And do consider a large water change or two to dilute the skewed dynamic in the tank> Is this also why my pH won't stay up at acceptable levels in the 8.2-8.5 range for longer periods?   <could also be the common summertime (and wintertime) dynamic of accumulated CO2 in the home from well-insulated houses and air conditioning. Do read through the archives about poor ventilation suppressing pH in the aquarium. Really very common> Do I need to use the Reef Builder more often or will the high kH in the reactor effluent bring the tank kH into more reasonable parameters after a while? <definitely not with a Ca reactor> I have just begun using the Carib Sea ARM media and it is doing a great job keeping the calcium levels up.   <I personally don't care for it... strongly favoring the quality of Knop media instead> Do I just need to wait it out for a few more days and see if the tank kH comes up more?  The tank calcium is the best it's ever been on a steady basis.  Once again, any and all help with the pH issue and the low kH would be greatly appreciated and please, please keep up the good work.  I read your FAQs every day and love all the Q&As.  Thanks for your help again, Jeff <thanks kindly Jeff. Overall, it really sounds like a fine tank and a small problem. No worries. (Re-)read the articles in our archives on understanding the Calcium Alkalinity dynamic... take comfort in the knowledge that Ca and ALK are rarely naturally (and safely) concurrently high... more of a hi-lo see-saw. As long as they are within the safe ranges (8-12 dKH, 350-425ppm Ca), then no worries. Best regards, Anthony>

- Calcium Reactor & Rising pH - Hello, I have a question that seems just the opposite of all that I have read on your site, I just set up a calcium reactor made by "My Reef Creations" it is a dual chamber reactor. The bubble count is 22 per minute and the drip rate is 3 drops per second. <Seems a little fast to me on both counts... should be about 15 bpm on the CO2 and 3 drops per two seconds on the effluent... but not a rule set in stone.> The effluent out from the second chamber is as follows: PH 7.2, alk 16 DKH and Calcium 500ppm. <These readings seem good enough.> I have been monitoring the tank parameters and alk and calcium are rising, but I have also seen the tanks PH rise daily sense the installation from 8.25 to nearly 8.5 over a weeks time. My question is will this stabilize or just keep rising? <Well, I'd like to say it would stabilize but it may not. What else is in your care regimen that you've not mentioned here - do you add Kalkwasser? Do you have an algae refugium?> The drip is going into my sump through a overflow bulkhead and is getting mixed with some air so I am thinking any excess CO2 is getting released into the atmosphere. <With a second chamber on your reactor, I doubt seriously that you have any excess CO2 at all. In fact, I would test the effluent before the second chamber... should be in the range of pH 6.5-6.7. If not, make some adjustments... it would seem in this case that you can afford your final effluent to be a slightly lower pH.> Will alkalinity from the reactor keep increasing the PH? <Not forever, but you do understand that the presence of buffers makes the maintenance of a higher pH much more easy. As I mentioned before, you should look to other things you might be doing - buffering top-off water, Kalkwasser, two-part additions as sources for a pH boost [as the most common trend in aquaria is towards a depressed pH] and stop those practices. A calcium reactor all on it's own won't raise the pH but the additional buffers along with the aforementioned practices could cause some problems.> Thanks Mike <Cheers, J -- >

- Calcium Reactor & Rising pH, Follow-up - Since the reactor has been set up I stopped using Kalkwasser, I do have a refugium inline, My PH prior to the reactor never climbed that high 8.2-8.35 was the normal range. The only additives I add is iodine. I do add buffer to my water before adding salt when making water for changes, but add no buffers to tank since setting up the reactor. I will try making some adjustments to the reactor to lower the effluents PH. <Sounds good. Let us know how it goes.> Thanks <Cheers, J -- >

High CO2/low pH 9/9/03 Hello Crew, <cheers> I have had chronically low PH in my 75G system. The tank is primarily  housed with LPS corals (open brain, torch, frogspawn, candy cane, Blastomussa (sp?). There are five fish (Coral Beauty 2", Kole Tang 3", six-line wrasse 1.5", Banggai Cardinal 1.5", and a Percula Clown 1".The tank has a 5" DSB with the following parameters: 380 Ca, alk - 3.5, nitrate <5, Temp 81-82. My PH ranges from 7.79 at night to about 8 during the day. I add 1 tsp of Kalkwasser per day with alternating doses of Reef buffer and reef calcium (Seachem). After reading about similar problems, I aerated a cup of tank water outside for one hour resulting in at .18 jump in PH. The tank has an internal overflow and a EV-120 skimmer. I have 4 maxi-jet 900s along with a Sen700 return for circulation. <ahh, yes... very common in well insulated houses> My question, I have not noticed any harm due to the low PH but I am concerned about the effects over time. If I were to connect tubing to the air intake of the skimmer and run it outside do you think that would take care of the problem. <very helpful to be sure, yes> I hate to start cutting holes in the side of the house to allow for the airflow. I live in Chicago and leaving windows open is only a solution for a few months a year. Or am I just chasing a PH level that is not necessary (8.2-8.4) given my set-up. Any and all help is appreciated. <please do try to maintain a higher/natural pH my friend. It will be better in the long-run. But don't worry about changing it overnight either. All in good time. Best regards, Anthony>

pH Fluctuation Hello WWM crew, Hopefully mine is a simple question. I have a 30g. reef with one Dottyback. Small mushrooms small yellow polyps , green star polyps torch coral and button polyps. My pH is 8.1 sal. 1.023, no ammonia nitrate at 25. my question is should I add baking soda to raise my pH to the 8.4 range and if I do how do I go about doing it. Thank you <Marty- I would recommend a pH buffer.  I use Seachem 8.3, and have only very small pH fluctuation.  Not too pricey, either.  Best of luck! Ryan> Marty

- High pH Problems - Bob, <Actually, it's JasonC today...> Hi...John Wilson from Brooklyn.  We met at the Brooklyn Aquarium Society meeting at which you spoke.  That was a fun night.  Thank you. Review: 65 gallon marine tank 1 yellow tang with no fins 2 percula clowns 1 engineer goby 60 lb? live rock macro algae that has almost completely died over the summer :-( My pH level has recently gone up to 8.6.  I have been adding baking soda daily for the past few days to try to lower it (1 tsp the first day, 1.5 tsp the second day and 1 tbls the fourth day) and it has not gone down.  Is this the right thing to do? <Not really... baking soda works fine to bring pH up from a lower number to about 8.3, but it doesn't work so well in reverse.> Should I add it in greater quantity? <No, I'd stop adding it at this point.> I couldn't find much info on lowering pH in your book or on the web.  Most pH problems seem to be on the low side. <True.> What could cause this rise in pH? <Perhaps something in your additive regimen... hard to say.> Would this be the cause of my macro algae die-off? <A possibility.> I have been adding Super dKH to the water I use to replenish evaporated water. <You might try just adding a lower pH top-off for now, maybe also a sizeable water change in the 25% range to attempt to get the pH back down a notch or two.> You mentioned something about periodically adding baking soda instead when we spoke at the BAS meeting. <Well... sodium bicarbonate [baking soda] is the most common buffering agent around, and is probably in the ingredient list of the stuff you are using now. The main advantages of baking soda are that it is cheap and easily available, and also difficult to overdose.> Unfortunately, I do not remember the details of this advice and, perhaps foolishly, did not ask you about it again. <No worries... again, it is probably more in your interest right now to get the pH back down to a normal level, and worry less about buffering for the moment. Start with an examination of everything you put into the tank, do a couple of water changes and see where you stand after that.> Thanks for your assistance and wisdom, John <Cheers, J -- >

That Time of Year... Depressed pH - Well-insulated Houses - 8/14/03 Hi, <howdy!> Have been researching the salt mixing process on your site, and have seen reference to buffering the RO water, prior to mixing salt, but could not find more specific details. <it's not rocket science, mate... we use RO or DI to demineralize water for the removal of the good and the bad. Then, simply buffer back with the good to a medium high/hard ALK and pH within the known safe ranges of seawater. Thus ensuring very consistent water every time (versus variable tap water quality)> Currently before mixing the salt, I leave my water to aerate for a day with a heater and powerhead in it, <very good> after which the PH tests at 7.4 prior to mixing the Instant Ocean. <not bad> Should I buffer this water prior to mixing? and if so, could I use my normal buffer, Seachem marine buffer? <yes... just a little would be fine to get closer to 8.0 or so> I am struggling somewhat with low PH in the tank, ranges from 7.9 to 8.2, and wonder if there is something I could be doing better.  Thanking You, Alastair <very common this time of year because of well insulated houses (depressing pH from excess CO2 in the house/water). Confirm this problem by taking a glass of aquarium water outside and aerate it heavily for 6-12 hours. Test pH before and after... there should be no change... but an increase would indicate the above problem. Much has been written on this topic in our archives at wetwebmedia.com if you care to read it. Best regards, Anthony>

- Low kH and pH - Hello again!!  I am searching for more answers if you great peeps can  help me out a bit. <Great peep Kevin here today ;) > I have the 180 gallon acrylic w/60 gallon acrylic below.  Both have numerous SPS and LPS stonies w/some softies here and there for looks <Haha, isn't it all for looks?!> and also a few clams and about 15 fish.  I have had the tank running for about 15 years and have not noticed any allelopathy between corals as I keep the corals away from each other. <Great success!> My tank parameters are: calcium 425, pH 7.9 if I don't add Kalk for a couple of days and 8.3 after daily doses of Kalk slurry per Mr. Calfo's book of coral propagation. <I think I've heard of that shady character...>  kH as of last night was 5 and 4.9 using the Tetra Test kit and the Sea Test kits respectively. On the very low side.  Sg. stays at 1.024 with the use of RO/DI by way of a switch and pump system I have been using for several months now. No nitrates, nitrates or ammonia. I use 2x400 watt metal halides and 4x110 watt VHOs for the lighting. <What 400w lamps are you using? I used to run 2x400w Iwasakis and have recently changed to 10k Ushios. The Ushios put out a beautiful crisp white light that really pops w/ VHO actinics.>  CPR SR9 skimmer with ozone and ORP controller.  I am using a Knop C calcium reactor with newly introduced Carib Sea ARM reactor media. I have found that it works great for keeping my calcium levels up.  The effluent is putting out 600ppm calcium and my effluent pH and kH are 6.68 and 28 respectively. Does any of this tie in with why I can't keep my pH from dropping rapidly after I dose the Kalk slurry at night? <Likely just excess CO2 from the reactor and/or poorer buffering ability from aged live rock. 7.9 is not a big deal.>  Usually drops .1  within 1.5 hrs. after dosing Kalk.  With a kH of 28 from the reactor will my tank kH come back up after a while of using the new reactor media or do I need to dose more often with Seachem's Reef Builder to bring up the kH and keep it up around 10-12? <Sounds like your Ca and alk levels are simply a little off balance. If you have some on hand, I'd bump the kH up with the reef builder just this once and you should be all set.>  I raised it up today before I left for work to 8-9 kH.  I am running 4-5 CO2 bubbles every 15 seconds and 90-110 effluent drops every minute to get an effluent pH of the 6.68.  Any suggestions here?  Please let me know if any of you (please feel free to discuss amongst yourselves) have any ideas. <Once you balance out your calcium and alk situation, you may want to richen the effluent a little by adding a little more CO2. Either that or add more Kalk slurry. It sounds like you're in good shape though, Good luck! -Kevin> Thanks again for all of your help!! It is truly appreciated. Jeff

Depressed pH in well-insulated homes (CO2 aaaagggghhhh!)8/5/03 Anthony, I performed the test you suggested and I also got the results you expected. Thank you for your insight! <it is a common but frequently misdiagnosed phenom of aquarium keeping in modern well-insulated homes. We hear it mostly in winter and summer when doors and windows are closed tightly> Just before lights out my pH was 7.87, at that time I filled a tea pitcher with water and added a small venturi pump and set it outside. This morning I sample the tank again and the pH was 7.84. I tested the pH of the water I was aerating outside and it was 8.23. <good work, mate> I have six CO2 generators in my home, and I don't think I can send them off to camp permanently, so what is a reefer to do? <heehee... it really is so much more than. A matter of greater air circulation overall in the house is needed> I know you've heard this before (I have read most of the archives on pH), but how do I fix this? I can not conceivably open a window in the Deep South in the middle of the summer. <understood... and not necessary. There are a couple of ways about this. If you have an attic fan... simply running the fan and having a window cracked slightly open in the room will often do the trick. Also... you can try piping air from a strong air pump into the aquarium (across the aquarium surface, into the skimmer, an O2 reactor, etc... whatever)> I have a pretty good protein skimmer and a tank turn over rate of 10x with an addition 600 gpm circulation from internal pumps. <understood... but this is a matter of the quality of air in the house at this point... not how it is processed by the skimmer, etc> My tank is 65g with a 29g sump and a 29g refugium (plants, snails, 2 clown fish & anemones). I would rate the aeration rate as good because of my tanks overflow, the return to the sump is very aerated, and the protein skimmer is very "foamy". <excellent> Forgive me, but I am a chemical engineer and I do not follow your explanation for my lack of "off gassing". The concentration of CO2 in the water is a function of the concentration of CO2 in the air plus or minus the consumption/generation rate of CO2 in the aquarium. <yep> The water can not off gas the CO2 beyond the equilibrium level of CO2 in the air. <exactly - the problem is that we cannot exhaust anymore CO2(converting carbonic acid by aerating/off-gassing) into the home until we change/shift that equilibrium in the atmosphere of your home with fresh air of a more favorable composition> Essentially the protein skimmer is a gas stripper or absorber and the concentration of CO2 leaving the skimmer is a function of the CO2 in the intake air. The protein skimmer will be a stripper if the CO2 generated is greater than the concentration of CO2 in the air, and it is a absorber if the CO2 consumption in the aquarium is greater than the CO2 concentration in the air. This is my understanding, but is that what you meant?   <indeed... engineers just always like to take the long way around the barn in explaining things. I'm not an engineer... but we have one in the family and I understand this all too well <G>> You said (referring to the source of CO2 in the aquarium): <if you mean "where does it come from", that would be respiration of photosynthetic organisms and other biological functions.>  I have to challenge this statement. Based on the amount of aeration I have in the tank I would suspect the water's equilibrium with the air to be the major source of the CO2. Do you agree? <nope... even without corals, anemones or significant plant growth (producing CO2 with respiration/photosynthesis)... you still have numerous other activities/faculties to do so... not the least of which is the significant microalgae/diatom growth that exists in any given tank. Do reconsider your position on the air being the primary source of your CO2 in light of unicellular algae in the oceans of the world and the roles they play. Its all about plants and algae, bud. Oxygen by day... CO2 by night> Unfortunately the tank is located in the middle of the house, but I can run an air line through the wall and into the attic...it will be a "fun" project! <heehee... fun: damn engineers. OK... agreed <G>> If the air line is connected to the intake of the protein skimmer, do you think this might solve my problem? <I do believe this will help> Do you have any other ideas? <yep... drink beer while you are doing it> I understand that it would take a tremendous amount of house plants to lower my CO2 levels in my home, and I am a very poor gardener of plants (unlike corals). <G>. I respect your opinion and I do not mean to challenge your very generous previous responses, <no worries/challenge at all... all in the pursuit of enlightenment. The unexamined life is not worth living... Si?> I just seek complete understanding. Your shameless plug for your book is not so shameless. The reef community receives an invaluable service through your website and you get compensated by "shamelessly plugging" an equally high quality source of information in your books. I think we get the better end of the stick! Thank you. Jeff <ahhh... much thanks for your graciousness. Best regards, Anthony>

Taking the hobby out of the hobby... AKA: One scientist's alternative to opening a window <G> 8/6/03 Hello Anthony! <hey Jeff... I just took a peek at the doctoral thesis you attached to your follow-up. I'm thinking of mainlining Jack Daniels just to get through it> I have quite a question for you. I am the guy who has too much CO2 in his house (I realize I am not alone). <I do recall, my friend :)> Instead of running a hose from the middle of my house through the wall and to the outdoors, I have come up with another solution. Why not scrub the CO2 out of the inlet to the protein skimmer using a caustic scrubber? <or... you cold just open the window in the room about one inch and pay a few extra dollars in electricity for the next month or two 'til the weather cools (if that). Of course, I may just be daft too> Imagine a 1 gallon container with a small venturi pump in the bottom, 1/2 gallon of 20% caustic (NaOH), and a sealed top with 2 "nipples". <it can't be all that bad if its got nipples... chat on> One nipple is attached to the air hose for the protein skimmer and the other nipple is an air inlet source. The venturi pump would pull gas from the inside of the container and fractionate it with the NaOH effectively scrubbing/reacting the CO2 out of it. The now nearly CO2 free gas will be pulled into the protein skimmer and will strip CO2 from the CO2 rich aquarium water into the CO2 deficient gas stream. The two will come into equilibrium and the net effect will be less CO2 in the exiting water from the protein skimmer. I do this at work all the time but on a much larger scale. This should work just like the test I performed last night. I took the aquarium sample and moved it outdoors and aerated it. All I did was "strip" CO2 from the CO2 rich water to the CO2 deficient gas stream. <I'm wondering if you like the fish and invertebrates in your tank or the science of water chemistry more? Seriously, Jeff... I have never seen anyone go so far out of their way to reinvent a wheel. Its not a bad thing... God bless you for having the mind and passion for analytical thought. But this is a very organic hobby. And this is the third e-mail where I am simply suggesting you crack the window open slightly. It may or may not work... but is very likely to at least help until the weather cools. And I cannot imagine that your house will immediately combust in summertime heat for the 1" breach <G>. Heehee... don't let me steal your thunder on this science experiment. But rest assured that I favor simpler solutions to this very common problem (attic fan, remote air pump, etc... all in the archives at WWM> I see this as a "widget" solution, but according to the attached material balance it seems like it would be relatively low maintenance. In theory 1/2 gallon of 20% NaOH will last about 2 months. I'm sure I would have to add some water because of evaporation. If my assumptions are right, then the molar reaction between the CO2 and the NaOH would be: 1 CO2 + 2 NaOH --> 1 Na2CO3 + 1 H2O What are your thoughts on this? Feel free to tell me I'm crazy! <you are crazy Jeff... now go take your meds. And please do let us know if your theory works... and if it requires napalm and storm troopers with flame-throwers to succeed. Be chatting soon. Anthony>

pH and air circulation 8/4/03 Anthony, Thank you for the very quick reply. <always welcome> Yes I have spent many nights reading the material on pH, but I want  to clarify your recommendation. Elevated levels of CO2 in the home will decrease the pH, correct? <essentially yes... or rather, excess CO2/carbonic acid in the aquarium not adequately off-gassed depresses pH> If I aerate the sample outdoors using an air pump overnight, then test the pH in the morning I should not have an increase in pH, unless it turn out that the air in my house has a higher concentration of CO2 than there is outdoors, correct? <basically... its a matter of the matter not escaping the aquarium because of well-insulted homes/inadequate off-gassing again> I have always found it easy to maintain my carbonate levels, could high CO2 levels possibly explain this? not always related... you can have high Ca, high ALK but low pH> What is the major input stream for the CO2... open top tank or my protein skimmer? <if you mean "where does it come from", that would be respiration of photosynthetic organisms and other biological functions. The skimmer and open top with an open window in the room are solutions/support> Is there a way to filter the air entering the protein skimmer to remove the CO2? <no CO2 from here bub... no worries. Its the plants, algae, corals, etc in your tank producing it> Sorry, this is a lot of questions. Thank for your help. Jeff <best regards, Anthony>

- Electronic pH Tester - Hey guys hope all are well, quick question, I am wanting to buy a Milwaukee ph tester for Anthony's Kalk slurry method. <Ok.> Which of the Sharp water proof testers would you guys recommend ph 53 ph 44 etc. <Most are very similar, and should probably depend more on your budget. I use a pH 44.> Have a great day! <You too.> Rocky <Cheers, J -- >

pH Issue - air circulation in well-insulated living spaces 8/2/03 I have read most of the PH FAQ's and have come to the speculation that my newly built house is the possible cause for having a PH that dips as low as 6.5 and as high as 7.9.   <yikes... and yes, not uncommon. Especially during summer with sealed houses and air conditioning> Both are frighteningly low numbers for a reef, and probably the reason many of my snails have died.   <ahhh...ya. Yep.> My fish seem to be ok for now, but I suspect it is only a matter of time if the PH remains that low. <do crack a window open in the room (and the door to the room leading to the house/on to the attic or other vents for cross breeze) and aerate the heck out of the tank> I have been adding Seachem Marine Buffer, but that as stated, it a temp fix. <agreed... better to aerate... but do confirm the issue by aerating a glass of tank water outside for 6-12 hours. The pH will increase if you are correct> My problem is that the reef is built into the wall and there is very little airflow in the main tank.   <can be corrected easy enough with a vigorous skimmer, O2/O3 reactor, etc> The Ecosystem mud filter is their largest and is in the basement and the main floor display is a 135.  But as I said, the wall above the tank is 6 feet wide and 2 feet deep.  There is a lighting canopy with MH/VHO in their and some room for fans, but I have been keeping the top covers on the tank assuming that the skimmer and open sump would provide enough aeration.   <agreed... but none can help if the house is still sealed. A cross wind from attic vent or other room window/door plus the slightly open window in that room are what's needed. Trust me :)> Please lend me your thoughts on how to deal with this problem.  Thanks! Adam <do the test on a glass of water first in the garage or outside (somewhere not sealed up. Then we can progress with a solution from there. Best regards, Anthony> -Low pH?- Morning folks! Well, this is getting ridiculous with the low pH.  Salt is 1.24, <Let's hope there's a 0 in there somewhere!> Mg is 1250, Alk is 11, Ca is 430, and pH runs from 7.9 to 8.1.  What the H&LL can be the problem with this low pH???!!! <Nothing wrong with that, my tank rarely breaks 8.1 and is consistently 7.9 or so at night.> I've attempted to add Kalk to raise the pH but it never gets above 8.15 or so due to the correctly functioning buffer. What in GODS name can FORCE the pH to stay low like this even with a good Kalk dosing???   <CO2> Before CO2 is mentioned, <Doh!> I've opened the windows in the room for days and have now run the skimmer air lines outside.  CO2 can't be the cause here cause I skim VERY well with dual skimmers in the sump, and after the window and air lines were done I got a modest .03 extra bump in pH. Man, I can't keep adding Kalk or the Ca goes wrong, pH swing seems decent enough so buffering appears reasonable and the alk is good with perfect Mg levels. What is causing this guys??  This has been going on for months and it's getting stupid now!!   BTW, the tank has never had an 8.1 to 8.3 or 8.2 to 8 4 swing in it's life of 1 year. <I see no problem here, everyone's tank runs at different saturation points and different pH levels. I wouldn't let it keep you up at night! -Kevin> Thanks for any help.

pH testing probes greeting fishy people, in my never ending quest for cool cheap gadgets , I came across this soil PH tester . Any idea if this sort of thing would work (assuming it covers the correct range)? <It may, not familiar with this device> I currently am using cheapo test strips which provide little to no accuracy given that the color scale jumps from 7.8 to 8.4 ... and of course the color I am trying to match to is somewhere in-between :P  I've read in some of the FAQs that digital PH probes can be found in the $30-$50 range, but have been having a hard time finding such devices. <try Aquatic Ecosystems, they have a renowned catalog and website> Being a long-haired, bearded Libertarian, I am a little freaked out about ordering something like this online from a hydroponics store..... we're all being watched.  Any suggestions/ideas/recommendations for these things? <definitely look into a good digital pH probe, they work well and last when taken care of> Oh yeah, my system: 180g FOWLR ~130lbs LR constantly re-arranged sand that used to be about 3 inches deep across the bottom of the tank Fimbriated Moray Eel (about 90cm) - the one who likes to keep all the sand in one big pile 2 Yellow tail damsels 1 blue devil damsel 1 cleaner shrimp DIY skimmer, wet-dry filter, rio3100 return pump,  2 Hagen 802s Ammonia 0 Nitrite 0 Nitrate ~40ppm - a constant battle with the eel Calcium 490 (source water responsible for 80-100) Alk 9.3 dKH Temp 81-82F , quite stable in that range Phosphates are quite high >2ppm, but I am surprisingly encountering little algae problems.  These are why I am looking into finding a more accurate measure of PH (that and I guess it would just be a good practice :D) so I can try and precipitate them out with Kalk after I get  my calcium down.  Ok, enough rambling.... thanks for your help Mark
<best, Chris>

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