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FAQs on pH, Alkalinity, Acidity 4

Freshwater pH question -10/29/08
Hello Crew,
<Hi,>
I've emailed you guys in the past with questions about my tanks, and you guys have always been great -- so thanks in advance for your help. My question concerns water pH. I've just moved to a new apartment and I'll be setting up a new tank, a 46g bowfront (I'm very excited about this!). I'm planning on doing a planted tank with angelfish, as I've always loved angels but until now have not had a big enough tank to keep them.
<In a tank this size, a school of six or more will be lovely!>
I'm a bit confused by the water in my new location, though, as it seems to be slightly on the soft side but with a pretty high pH. With my home test kits I get a kH of 6 degrees, and a pH of 7.8 (I don't have a general hardness test kit yet).
<Easily accepted by standard commercially-bred Angelfish. Do please check you're using water out the tap, not from a water softener. For what it's worth, standard Angels are happy between pH 6-8, 5-20 degrees dH and at hardness level up to around 10 degrees KH.>
I've looked up the municipal water quality report for my area, and the values they give are pH of 7.9, total hardness of 109 mg/L, and alkalinity of 96 mg/L (seems to be reasonably in line with what I'm finding with my home test kits). So, my questions are: 1) why is the pH so high even though the water doesn't
seem to be too hard,
<pH isn't solely dependent on the carbonate/bicarbonate salts measured via KH test kits. In any case, pH doesn't matter. Hardness matters. So long as the pH is stable from week to week, your water supply is fine. Just add dechlorinator and enjoy!>
and 2) should I set about trying to adjust the pH in order to keep angels?
<If we're talking about standard hybrid Angels from the pet store, then you're going to be fine. They've been bred in a wide range of conditions, and are essentially extremely adaptable animals. Wild-caught Angels are a whole different kettle of fish though, as are carefully bred species such as Altum Angels and Dwarf Angels.>
The water quality report mentions that the pH of the water supply is raised in order to prevent pipe corrosion, but doesn't say through what means.
<Shouldn't worry too much; good quality water conditioner should fix things.>
As far as what to do about it, I'm considering doing something not too drastic like adding a bit of peat in a media bag to the filter. Do you think this might help? I don't want to undertake anything too drastic with this tank (such as finding another source of distilled or softer water for mixing in), but I'm concerned that a pH of 7.8 is too high for angels, and also possibly for plants.
<It all depends on what you're keeping. Yes, wild Angels come from water that is fairly soft, though not usually those really soft blackwater habitats we associate with Discus. The tank-bred Angels are adaptable and really more fussed about water quality. Likewise most plants adapt well to hard water, and indeed some prefer it (Vallisneria for example, and some Amazon Swords). Just as with the fish, pH isn't something to lose sleep over except in very specific situations. Regardless, it is ALWAYS better to chose fish and plants that will thrive in the water chemistry you have, than to obsess over methods to alter the hardness to suit the fish you see in books.>
thanks again,
Nicole
<Cheers, Neale.>

pH problems 10/9/08
Hello. I have a problem with the pH in my tank. I've had it for over two years now. It's a 70 gallon tank, with three fancy goldfish. I do 15% water changes every week, and I always use a chlorine/chloramine removing product (stress-coat). My Ammonia is 0, nitrates are 10ppm, and the pH is now a very low 6.0.
<Much too low for Goldfish... stressing them for sure, and eventually making them more prone to disease.>
It wasn't always like this, it used to be 7.0 (my tap water has a pH of 7).
<At the very least do more water changes: the more pH 7 water you add, and the more frequently, the smaller the pH drop between water changes will be. Do read these articles to learn about water chemistry:
http://www.wetwebmedia.com/FWSubWebindex/fwsoftness.htm
http://www.wetwebmedia.com/FWSubWebindex/fwh2oquality.htm
With Goldfish, you should be doing 25-50% water changes, weekly.>
I have no idea what to do. Could the problem be my filter?
<Not as such, unless there is peat or something else acidifying the water in there.>
I have an emperor 400, but I never replaced the pads inside. Can that be causing the problem?
<Well, any chemical media (e.g., carbon) need to be replaced at least monthly to do their jobs. One reason I consider carbon a waste of time. Likewise ammonia remover (zeolite). Both these products are incredibly cheap to make but the "modules" the company sells are wildly inflated, so in both cases these things are in your filter not to help with water quality but to extract cash from your pocket and direct it into the coffers of the filter manufacturer. I always recommend people get basic canister or box filters into which you can stuff whatever media you want. In the case of Goldfish, all you need is some mechanical media (such as filter wool) to extract solid waste, and then lots of biological media (such as ceramic noodles) to process the ammonia. Nothing else is essential, but you still have the option of removing some of either media to make space for any specific media you need, such as crushed coral or peat or whatever. For all these reasons, hang-on-the-back filters are, in my opinion, a waste of money.>
Also, I have bought a big bag of crushed coral to try to buffer the water. Should I use it, and if yes, how?
<Yes you should use it. Put some (say, a cup) of crushed coral into a media bag (something that looks a bit like a sock but made from mesh fabric). Rinse the bag under a running tap to wash away all the dust. Place the bag into the filter. As the water flows through the crushed coral it will pick up carbonate and bicarbonate ions, and this will neutralise the acidity gently but effectively. Use a pH test kit daily for the first week just to make sure the pH isn't changing too rapidly. If it is, remove some (say, 50%) of the crushed coral and put the bag back in the filter. Keep testing, and adding or removing crushed coral until you get a nice steady pH around 7.5 between water changes.>
My filter doesn't really have much room for a lot of it.
<That's why I wouldn't have recommended the hang-on-the-back filter. Unfortunately there's not a lot you can do here. The best solution would be to buy a cheap box filter (cost around £5 here in England) and an air pump (if you don't already have one). Put the crushed coral in the box filter (no need for the media bag in this case) and then connect to the air pump. As the air bubbles through the box filter, water will flow past the crushed coral, buffering the pH.>
Please help me. Thank you.
<Cheers, Neale.>

Re: pH problems – 10/10/08
Thanks Neale that was very helpful. Now let me just bother you with one more question. Do you think I can just place the crushed coral in a fine mesh bag and just lay it on top of my substrate and putting an airstone next to
it instead of using a box filter?
<Nope, won't work. Filtration -- whether chemical, biological or mechanical -- relies on moving water being moved past the media. This is why floating a sponge in a tank doesn't turn it into filter -- the water has to be pumped through the sponge. Moreover, once the chemical media gets covered with algae, bacteria and silt, it becomes isolated from the water, and so stops working. You need to be able to clean the media every few weeks under a hot tap to wash away this stuff. Putting the crushed coral in a filter -- whatever type of filter -- is the only way this system works reliably. Notions based on adding coral sand in the gravel or putting tufa rock in the tank won't work for the same reasons. Without a flow of water and regular cleaning, any chemical buffering offered initially will fade away in a few weeks.>
Or do you think this could just trap a lot of waste and become a hazard to the aquarium?
<Indeed.>
Your help is much appreciated.
<Cheers, Neale.>

ph, FW... modifying 4/16/08
Good day,
I have a pH question that I have searched for an answer on but have not found or I may have overlooked. I know there is a ph range for fish that are listed, I know that different water has different buffering ability and that aragonite, peat, coral, etc can alter pH either up or down. What I am trying to find out is that most literature gives the desired pH range for different fish/species, or says adaptable but to avoid extremes....what would an extreme be, especially in the alkaline range? Is 8.2 an extreme for a 7.5 fish even if it is a consistent 8.2? I really don't want to attempt to combat this with ph altering chemicals, nor do I want to be restricted to African cichlids that will destroy my plants :-(
K
<K, very simply, most standard community fish will do well between pH 6 and pH 8. The main exceptions are the livebearers, which absolutely must be kept at a basic pH above pH 7. Now, having said this, pH isn't what you should focus on. Fish don't really care about pH all that much; what matters to them is pH stability. In other words, it's the carbonate hardness, measured in degrees KH. For standard community fish you want a carbonate hardness around 3 to 7 degrees KH, and for livebearers you want at least 5 degrees KH. Why don't I mention general hardness (measured in degrees dH)? Well, while this is also important in terms of accommodating "soft" and "hard" water fish, it doesn't directly steady pH. Rather, general hardness affects the osmoregulation of the fish. So what you're after for standard community tropicals is water with a general hardness between 5-20 degrees dH, 3-7 degrees KH, and between pH 6 and 8. This range is fine for species that are said to be adaptable, like Corydoras and barbs. You might not be able to breed them, but they'll live just fine. Livebearers are exceptional, and must have hard (10+ degrees dH), carbonate-rich (5+ degrees KH) water with a pH around 7.5-8. Do have a review of this article:
http://www.wetwebmedia.com/FWSubWebIndex/fwh2oquality.htm
Cheers, Neale.>

Re: pH 4/16/08
Thank you. That was exactly what I was looking for. There is so much emphasis (and products) revolving around actual ph that never mentions the hardness or buffering, so it leaves a lot of uncertainty for non-chemist hobbyists like myself :-) .
<Indeed so. Because pH is easy to measure and understand, people tend to focus on it. But at best, what pH does is give you a first glance look at water chemistry. It doesn't tell the whole story.>
So if my dh and my KH are spot on (11 and 6 respectively), a steady pH of 8.2 is ok for fish that are known to do well do in ph 7.5-8.0?
<You should be fine; this sounds a lot like "London Tap Water" and provided you avoid fish that explicitly demand soft and acidic water to do well (like Ram Cichlids and Rasboras) you should find many species do well. Livebearers are the obvious choices, but Rainbowfish, Barbs, Halfbeaks, Gouramis, Plecs, and Corydoras can all be relied upon as well. Most hardy tetras are okay, but to be honest Neons and Cardinals are of variable use in very hard water and are perhaps best avoided. X-ray Tetras on the other hand thrive in such conditions. So research your choices carefully. Cheers, Neale.>

High Nitrates after use of Melafix – 03/20/08
Hello,
<Hi there>
First, let me say thank you for your wonderful site, which I return to every chance I get. You have been kind enough in the past to help me; and I am hoping for your assistance again.
<Will try...>
I have a 36 gallon freshwater tank, lightly stocked with 10 fish. When my tank was new (15 months ago) it always had an alkaline PH of about 7.2.
<... Mmm, not "that" alkaline... In fact, some good reasons to have a slightly elevated pH... NealeM has a nice article re: http://wetwebmedia.com/FWSubWebIndex/fwhardness.htm
and the linked files above>
As my tank matured, I was told that it would probably become more acidic, which it did. It has been around 6.6 for the past few months now. However, 2 weeks ago, my Boesemani rainbowfish got injured in a castle ornament (which I have since removed) incurring significant scale damage. I added Melafix
<...>
to the tank because I had heard great things about it speeding up healing. Well, it worked. He was completely healed within a week.
<Might've taken seven days (or less) w/o...>
I was performing modest 10% water changes every other day for the length of the 7-day treatment in an attempt to keep the water pristine. During the course of the treatment I only tested for ammonia and nitrite to ensure that my bio filter was not being affected. Ammonia and Nitrite always tested at zero and continue to do so to date.
After treatment ended, I put carbon in the filter (Eheim canister) and performed a 25% water change. I tested my water parameters a few hours later and was very surprised to find high nitrate levels of at least 40ppm, but could possibly have been higher. It is very hard to differentiate on my test kit at any level higher than 20ppm since the shades of red are almost identical.
<Mmm, often diluting samples by half (by adding "clean" water of the same approximate volume...) can/will bring readings back "on scale">
My nitrates never exceeded 20ppm before this, as I religiously perform 25% water changes every two weeks with a complete gravel vacuuming.
I theorized that the Melafix must have been responsible since it is a plant derivative and probably contributed to the dissolved organics in the water.
Could this be the reason? Also, as I feared, my PH level has dropped to the lowest range on my test kit (6.0-6.3).
<All are possible interactions, yes>
I have been doing daily 15% water changes since this occurred and the nitrates seem to be dropping (hard to tell once in the "red" range on the test kit) and my PH did go up temporarily last evening to 6.4, but had dropped again by this morning. I don't wish to stress my fish, who all appear fine at the moment, so I hesitate to do large water changes for fear of the PH rising too quickly.
<You are wise here>
Should I proceed with the daily 15% water changes, or do you feel that this is insufficient to correct this issue in a more timely manner.
<I would continue as you are>
Is there anything I could have missed (besides the obvious of not using Melafix in my display tank anymore). I thank you in advance for your assistance.
Michele
<Mmm, I think you're doing fine. I am NOT a fan of the "fix" products by API, but there are folks here (WWM) who are a bit more charitable. Am a bigger promoter of the use of real medicines. Bob Fenner>

Follow-up on High Nitrates/low PH after Melafix use
Hello again,
<Michele>
I wrote to WWM earlier in the week regarding experiencing high nitrates and subsequent low PH in my tank after using Melafix to treat a injured fish.
<I recall>
For your reference, I have included my original correspondence which Bob Fenner answered and was kind enough to assist me with. I have been doing daily modest water changes to bring down the nitrate levels, which has vastly improved (currently reading in the 20ppm range) but of course I'm still working on getting it even lower. However, in tandem with the high nitrates, my PH level dropped from 6.6 to the lowest range on my test kit (6.0-6.3). Water changes have resulted in the PH rising to 6.4, but this effect has been temporary, usually dropping back down within 24 hours.
<I would bolster the alkalinity here with at least a few teaspoons of baking soda... or a commercial prep.... Covered on WWM>
I realize that larger water changes would yield quicker nitrate reduction, but I don't want to stress the fish in case the PH does increase too rapidly so I'm proceeding cautiously.
<You are wise here>
But despite the nitrates being reduced, the PH is not climbing back up as of yet and stabilizing as I had hoped. I was somewhat puzzled about this, so I went to your site and researched some possibilities as to why. In doing so, I realized that I did not know what the KH or GH of my source water was, so I purchased a KH/GH test kit to find out.
<Ahh!>
I live in New York, and we have very soft water, which has almost no KH/GH, which I confirmed with the test (only 1 drop yielded a slight tinge of color). I know now that this is not ideal, and that PH drops can occur without enough buffering;
<Yes>
however I am very leery of adding any chemicals to the tank for fear of rapid and/or wide PH fluctuations which can be much worse than a stable but low PH.
<Best to make all such changes gradually, through/by way of the change out water... modify it and add it to the system>
My father has been using the same source water for 30 years, and has successfully kept tropical fish without the use of any chemicals to alter PH or hardness. His philosophy is to keep fish that will adapt to your conditions and thinks I am overly concerned about this.
<A valid concern; particularly if only keeping livestock that "enjoys" softer/acidic water...>
I tend to agree with his philosophy but my real concern is the low PH hindering the nitrifying bacteria.
<Also a valid concern>
I have read that at lower PH levels, the bio filter does not work as efficiently.
<This is so>
Is this true, or does PH have to much more acidic for this to occur?
<Slightly alkaline is better... the forward reactions/nitrification are reductive in nature... drive pH down... so having some biomineral in place...>
If I continue with the daily water changes and get the nitrates down to about 5-10ppm and keep them there with a more frequent maintenance regimen (perhaps a weekly water change instead of bi-weekly), will the PH increase to where it was a few weeks ago, or without sufficient KH will it remain low no matter how many water changes I do?
<If there is no addition of alkaline material (esp. carbonate, bicarbonate) from somewhere, the GH, KH will not change... If reductive processes continue, the pH will drop...>
Forgive me if this has been explained somewhere on your site.
<An, no worries>
Be assured that I have been reading, but I find this issue of hardness somewhat confusing and wanted to check with someone from the crew before deciding on a course of action. Also, please note that prior to adding the Melafix a few weeks ago, I did not have excess nitrates nor any problems with a sudden PH drop so I am hoping that just keeping the nitrate level extremely low will get my tank back to where it was a few weeks ago. I had also read Neale's suggestions to some people about using crushed coral in the filter to raise KH, but I don't want my PH to rise by very much.
<Depending on how much, how soluble, this addition is very safe... will not raise pH much, very quickly at all>
Since my source water is on the acidic side (6.6-6.8), my goal is to get the tank PH as close as possible to my source water. Is it possible to use the coral and only increase the KH and PH slightly rather than to the basic side of the PH scale?
<Yes... could be placed in a filter, bag... in a container with your make-up water... allowed to "soak" for a few days...>
I'm somewhat confused because I have been hearing/reading conflicting information about their use. How do you suggest I achieve my goal of increasing my PH to about 6.6 - 6.8 and stabilizing it?
<Mmm, the water changes you're doing... with the addition of a bit of sodium bicarbonate (very safe) or a modicum of commercial aquarium pH buffering product>
Once again, your advice is greatly appreciated and invaluable.
Michele
<Let's keep chatting this over till you feel comfortable with your understanding of the underlying principle/s here... This aspect of water quality (pH, alkalinity/acidity... "hardness") is too wordy in English unfortunately... But once you grasp it... Cheers, BobF>

Re: Follow-up on Discovery of Low KH after High Nitrates/low PH w/Melafix use 3/26/08
Hello Mr. Fenner,
<Just Bob please Michele>
Thank you so much for all of your assistance in explaining how KH factors into maintaining PH. I have been doing some more reading and if I am understanding correctly, the baking soda method needs to be replenished with each water change (outside of the system in the new water) .
<Yes, this is best>
Since I'm not great at chemistry, and thus would be experimenting with the amount to use to reach my goal, I fear that this leaves a lot of room for human error.
<Actually, not much error possible. This practice, with Baking Soda is quite safe>
So I think I feel more comfortable with a slow soluble carbonate substance such as crushed coral or even crushed oyster shells and will experiment with a small amount in the filter as a first corrective step to increase KH. The only crushed coral I have been able to find however has aragonite mixed in as well. If I understand correctly, this makes it more soluble, so is this still acceptable for my purposes or would this make the tank too alkaline?
<No, not likely>
If not recommended for my purposes, I have also been able to locate crushed oyster shells packaged as a "bird feed".
<Ahh! This material... usually some type of Dolomite ("Tapa Shell)... a compound of calcium and magnesium carbonates CAN be very soluble... and a mess to handle/deal with... too "cloudy" in preparation/use>
In the meanwhile I will continue with my water changes to further decrease the nitrates and proceed from there. Thanks for the offer/opportunity to continue chatting until I get a better grasp of the subject matter. I'm honored that you would take additional time from your busy schedule to assist me.
Michele
<Am out in Malaysia currently... where am dreading the Net slow-down. Cheers! BobF>

Re: Follow-up on Discovery of Low KH after High Nitrates/low PH w/Melafix use 3/30/08
Good evening Bob,
<Mich>
I hope your trip to Malaysia is going well.
<Yes... but the Net is slow... and intermittent>
I did purchase the crushed coral and added a very small amount to the filter on Tuesday. I figured I could always add more if needed. Since my nitrates are now in 10ppm range, I've stopped the daily water changes and will continue as necessary to keep them low. The PH was holding steady at 6.4 for a couple of days without dropping.
Today it has increased to 6.6, so it seems that the coral is working. My KH test kit still is reading very low (1 degree), but I'll give it some more time since I seem to be making some progress. And speaking of progress, I actually managed to talk my father into adding some coral to his filter as well.
<Ahh!>
I referred him to your site and our discussions; and I guess he realized that no matter how long you've been in this hobby, there's always something to learn.
<Is so for me... and I am indeed an old timer in the trade, science and hobby>
Thanks again for your help. I have been enjoying chatting with you.
I will keep you posted on the progress of my tank, but I'm confident that the coral will serve the purpose.
Michele
<Bob Fenner>

Re: Fish suddenly sick, FW, pH shock 3/3/08
Hi Crew,
This is unfortunately an emergency. I have been keeping my fish (6 zebra Danios, 3 Cory cats) in a separate tank for about a week and a half while their normal tank cycles with added ammonia. The tank they're in now is a half-full 20 gallon tank with a heater (temp has been constant at 74F) and bubbler instead of a filter because the filters are in the normal tank, hopefully building up bacteria. I have some "Ammo-Chips" in the temporary tank to soak up the ammonia since there isn't any established bacteria. I've also been changing the water in the temporary tank often with tap water conditioned with Amquel. I did this yesterday (actually, I added about 20% additional water since there is extra space in the tank) and I swished the net around to grab some of the floating "gunk" and cleaned a lot of that out. All seemed to be well this morning, but I came back tonight after being gone the whole day and my smallest Cory was dead and the rest of the fish were looking very sick. Some were hanging near the top; others at the bottom. They don't seem to be breathing hard, just very listless. Ammonia and nitrite are zero. I don't have a nitrate test kit, but I change the water regularly and I doubt it could make them sick this fast. It would seem like it had something to do with the water being added or the "gunk" being taken out, although I did what I always do (add Amquel and get the water to about the same temperature as the tank water). I now have the fish out of that tank in a Tupperware container with the bubble wand. I added some Prime and some Stress Coat even though there isn't an ammonia or nitrite problem. (I didn't know what else to do!) The water has been pretty cloudy in the tank, but I think it's because there isn't a filter, only a bubbler for oxygen. If it were a lack of oxygen they would have been showing signs of distress earlier. And if it was poisoning due to the decomposing "stuff" in the water, wouldn't I see some ammonia or nitrites? I have antibacterial food on hand and I'm going to feed that to them, if they'll eat. I have no idea what happened, unless the water wasn't dechloraminated well enough, but I feel like I always add more Amquel than necessary just to be safe. I don't have any clues! They all look like they're barely hanging on.. I appreciate any help you can offer.
Thank you so much,
Allison
Hey Crew,
I just realized the problem: pH shock. I tested the tank - pH 6.0 - and the tap water - pH 7.8 or more. Basically, the tank and the tap are at opposite ends of my testing kit's scale, I guess because of aeration in the tank bringing the pH down. I guess all I can do now is just hope for them to survive. Please let me know if there's anything else to do. I'm going to put them back in the tank (since now they're in the Tupperware container).
Thanks,
Allison
<Hello Alison. Glad you figured out what the problem was. Yes, pH can make a big difference to how well (or otherwise) fish settle in. Maintaining a steady pH between water changes is essential. If the pH in your aquarium is dropping from 7.8 to 6 within a week, then you have a serious instability problem. Have a read of these two articles:
http://www.wetwebmedia.com/FWSubWebIndex/fwh2oquality.htm
http://www.wetwebmedia.com/FWSubWebIndex/fwsoftness.htm
Essentially the problem is likely that your water has no carbonate hardness (use the "KH" test kit for this) and so pH drops rapidly. One common mistake people make is to use water from a domestic water softener: do not do this! However hard your tap water might be, it's fine for most fish. In some ways hard water is a positive asset.
http://www.wetwebmedia.com/FWSubWebIndex/fwhardness.htm
In the meantime, your fish should recover from the pH shock. Obviously don't feed them, and don't fuss over them either, as that'll stress them. Leave them somewhere dark and well oxygenated to they can recover at their own pace. If they don't survive, at least learn from the experience and read up on water chemistry. Note that everyone thinks they understand pH, whereas the pH value itself actually doesn't matter all that much -- what matters is pH stability. And for that, you need carbonate hardness. Cheers, Neale.>

pH drop, FW, no reading on Alkalinity 2/25/08
I am having problems with my ph and don't know why. About two months ago I got a new 45 gallon aquarium. I've had an aquarium for many years and never have had a problem like this. I used much of the same water from my other tank. I got a new HOT Magnum 250 canister filter. I used all the same decorations. The only thing I added new was a banana plant. I took it out and threw it away after I first had problems. The gravel I used is the same that I have in a smaller aquarium. For about a month after I got it set up my fish were doing great. I got some Blue Rams and they did good for about a week then died.
<!?>
I got some more and the same thing happened. The same thing happened with my small new Green Severums after a few days (they didn't look good when they came in so I didn't think much when they died). I just thought there was something different with the fish because everything else was fine. Then suddenly overnight my fish became less active, mostly Angels.
<... something very wrong here>
I checked the ph and it was about 6.2 and usually it is about 7.4 and our tap water is around 8.0. Slowly I lost some bigger Angels that I had had for about 8 months and then the smaller ones died that I've had for about 3 months. Now I'm only down to one smaller Angel. I was okay when the Rams and Severums died because they were new, but when the Angels that I've had for awhile died I knew something was wrong. I do a water change to raise the ph up. It goes up for a few days then drops back down. The weird thing is everything else is doing good. My Neon Tetras, Koi Swordtails, Boesemanni Rainbows, Green Tiger Barbs, small Plecos, and Cory Cats are doing just fine. Why are just my Rams, Severums, and Angels dying? Why is my ph dropping and what do I do to keep it up? Thanks for your help.
Cole
<You have quite a mix of fishes... Perhaps the Cichlids are/were of "low quality"... many imported ones are quite touchy. I suspect your water has low alkalinity, and that you haven't read... Start here: http://wetwebmedia.com/FWSubWebIndex/fwph,alk.htm
and the linked files above, part. Neale's piece "In praise of hard, alkaline..." Bob Fenner>

Help!! Ph Crash?? 01/13/2008
Hello WWM crew,
<Hello,>
This might be repetitive, but as always, got to congratulate and admire the services you people do. If this question once again gets to Neale, I would like to thank him very much for all the past help he has given me. Anyhow, I have a very weird situation on my hands and hope that you could help.
<Weird away...>
I currently have a 170 and 55 gallon freshwater tank that I do a 50% water change weekly with aged tap water (both tanks has been up for approximately one year). As of last week, my PH value is at 7.6 for both my tanks (common stable). As of today, I checked my water parameters and found that the PH for my 170 gallon tank is at 6.4!!!
<OK, that's a big swing and definitely not good. Not fatal, but not good. Does suggest a lack of carbonate hardness, which is at least relatively easy to rectify.>
I have two test kit that I verify with (API liquid test kit and Mardel quick dips). This have never happened to me before. The only thing that I have done differently since the last water change was change my brand of dechlorinator, from Prime to Amquel+ and NovAqua+ due to the great reviews that they have gotten.
<If one dechlorinator removes ammonia from the tap water but the other doesn't, then the ammonia can result in a higher-than-expected pH reading. But a quick check suggests that both Amquel and Prime remove ammonia. Not sure NovAqua does.>
The tank does have a large piece of driftwood that has been in it for about one year now.
<Bogwood will lower the pH by producing acids that neutralise carbonate hardness. That said, a moderate amount of aged bogwood shouldn't have a huge effect except in very soft water aquaria.>
I can't figure out what could be shifting the Ph so much. Could the new dechlorinator be affecting my readings?
<Can't see why.>
This also seems invalid due to the 55 gallon tank reading normal as always. The 170 is currently equipped with three 405 Fluval canisters, and a Vortech MP40 powerhead, which apparently by itself pushes 3000gph.
I think I do have ample circulation. Total hardness for the tank reads approximately 120ppm and total alkalinity at 0ppm.
<Ah, here's at least one issue. Alkalinity is essential to any aquarium. Total hardness itself is of secondary importance, and is mostly about how fish osmoregulate. Carbonate hardness (measured in degrees KH) is far more important, as it tells you how well an aquarium prevents pH changes. As things stand now, if you have zero alkalinity, which would suggest zero carbonate hardness as well, your aquarium has next to no ability to resist pH changes. This is because the other minerals in the water (the ones making total hardness) don't combine with acids. All they do is float about in the water.>
Very awkward. Tank is currently stocked with one L25 Scarlet Pleco at 10" and one 6" Flowerhorn cichlid.
Ammonia at 0, Nitrite at 0, and Nitrate at 30ppm. I have not seen any adverse affect on the fishes as of yet. I plan on setting another batch of tap water overnight tomorrow with dechlorinator and perform a change on Sunday.
Its early Saturday morning right now. Any ideas?
<Raising the carbonate hardness is essential for Flowerhorn cichlids, given their Central American ancestry. I'd suggest making up a batch of Malawi Salts, and adding these at a 25% to 100% dosage until you get the right set of pH and carbonate hardness (i.e., KH, not total hardness) values for your needs. You can buy these salts from stores, or you can make your own. Here's one handy-dandy recipe for Rift Valley salt mix:
Per 5 gallons/20 litres
* 1 teaspoon baking soda (sodium bicarbonate)
* 1 tablespoon Epsom salt (magnesium sulfate)
* 1 teaspoon marine salt mix (sodium chloride + trace elements)
Mix well, dissolve into the bucket of water, and then add to the aquarium. Don't do huge changes at once, but do water changes of 25% per day until the tank is where you want it in terms of pH and carbonate hardness. I'd recommend at least 7 degrees KH, and ideally 10+ degrees KH, for most Central American cichlids. You should find this prevents pH changes completely.>
Also, is it possible for water quality to remain cloudy due to insufficient surface area for the bio load to attach to and stabilize and remain free-floating? I really doubt that I am overfeeding since I feed usually once a day and make sure all food is consumed. Right after a major water change, water would be crystal clear for a day or two and would get cloudy again. It has been like this ever since I started. No problem of this on my 55er.
<Curious. But no two tanks are the same.>
Lastly, any opinions on Prime vs. Amquel+/NovAqua+?
<None. Never used either.>
My only concern is the
concentration levels. Prime seems to be so much more concentrated, at 5 mL per 50 gallons of water. While, Kordon's product suggested dosage level is at 5 mL per 10 gallons. Any thoughts on either product?
<Nope. All dechlorinators do the job, so I tend to buy whatever is on sale! This sort of thing may matter more for fancy-pants marines, but freshwater fish generally don't care so long as the chlorine is removed.>
Ok, that's all for now. All help is greatly appreciated. Thank you so much and be safe. Andy
<Or as we say in England: "Be good, or if you can't be good, be careful." cheers, Neale.>

Re: Help!! Ph Crash?? 01/13/2008
Neale,
<Andy,>
Thanks so much for the help, again :) I will do as per your instructions.
Anyhow, any idea what could have caused the PH to shift so massively?
<All aquaria have a downward pH trend. What varies is the speed with which the pH drops.>
My water at the tap (which I use for water changes) has a PH of 7.6, total alkalinity of 120ppm, and total hardness of 250ppm. What happened to my alkalinity and carbonate harness?
<If the pH drops, that means the carbonate hardness got used up! So you have two options: do more water changes, so the pH doesn't drop far between water changes, or else raise the carbonate hardness so the pH drops more slowly. Simple, really.>
I do, do 50% water changes weekly.
<Clearly not enough given all the things going on in your aquarium. Every aquarium is different, so all you can do is use test kits to monitor changes, and then alter the maintenance regime to slow those changes down.>
Well, thanks for the help and hope all is well. Andy
<Hope this helps, Neale.>

pH Crash, fish symptomology 12/31/07
WWM Crew,
Happy New Year. Can you please tell me what are the signs and symptoms of fish reacting to a pH crash?
<... often a loss of orientation, rapid to deep breathing, setting on the bottom, death...>
And what causes a pH crash?
<Uhh, a loss of "buffering capacity" and action/substance to shift it (pH) in one direction or t'other...>
How to save your fish when the pH crashes. Thanks in advance for your help - Jean
<... please see WWM re freshwater, marine... pH... Your answers are there. Bob Fenner>

Question on pH, FW 12/18/07
Hello, My water at my house is odd, it has a pH of about an 8.0?
<Ours is higher...>
and a carbonated hardness of around 2. I wanted to get a pH of 7.0 and a higher carbonated hardness to stabilize the pH, so I set up a fake aquarium
<?>
and tried to obtain this. I had heard that sodium bicarbonate, baking soda strengthens the carbonated hardness but increases the pH, so I thought of the pH spectrum and came across lemon juice. I first used lemon juice to lower my tap water pH of 8.0 to a pH of 6.5. I then proceeded to add some baking soda to stabilize the pH by increases the carbonated hardness and at the same time higher the pH to a closer 7.0 and it worked. would using lemon juice and baking soda be a safe thing to do at the start of the setup of an aquarium to establish a stable pH. It not like I used a whole lot of either of them as well, about 2 table spoons? of lemon juice and a teaspoon of baking soda in? a 10 gallon aquarium made the ph and carbonated hardness perfect.
Thank you,
Jason
<Unfortunately the citrus has more to it than acid... I would start with more "just water" here. Please read re: http://wetwebmedia.com/FWSubWebIndex/fwmaintindex.htm
the second tray down. Bob Fenner>

pH and KH lowering, FW 11/26/07
hello! I have been struggling with PH and KH problems for 2 years now. I used to keep African cichlids so lowering Ph and KH was never a problem-until I decided to get tropical fish instead.
<Oh?>
In my 29 gallon tank, the PH rests at about 8.5 and the KH at 17. Something that shocked me was that the GH tested at 2. (could high PH and soft water exist?)
<Ah, you're getting your wires crossed here. A general hardness test kit measures calcium oxide. Some test kits translate the results into the equivalent hardness in calcium carbonate for historical reasons (I believe this is primarily in the US, but could be wrong). Regardless, the chemicals involved are measuring calcium oxide. So, a general hardness reading of 2 degrees dH means there is a low concentration of calcium oxide. Nothing more, nothing less. A carbonate hardness test kit measures carbonate and bicarbonate salts, and gives the result in a scale based on concentration of calcium carbonate. So, a carbonate hardness of 17 degrees KH means there is a very high concentration of carbonate and bicarbonate salts. Yes, you can have these two things happening at the same time. Imagine a glass of water into which you'd added some salt and some sugar. One test kit might measure salt, the other sugar. Simply because one was high wouldn't mean the other would have to be low, because they're independent variables. While it is *often* true that water with a high carbonate hardness often has a high general hardness as well, there's no natural law that says it has to be so. It's merely something that tends to happen for various geological reasons.>
I also decided to test my tap water. The PH was a perfect 7, KH at 17 and GH at 2. I suspect my high KH to be altering the PH.
<Carbonate hardness does tend to raise pH, yes. But so too will ammonia, so check that.>
I used to have rocks in my 29, but I took them out about a week ago.
They were boiled prior to, but I highly doubt this has anything to do with the problem.
<Boiling calcareous rocks (such as tufa rock) will have precisely zero effect on whether or not they raise the carbonate hardness.>
I have searched online a bit, and one recommendation was to mix water with Hydrochloric Acid... sounds incredibly risky and dangerous, but could be worth it.
<No, no, no. There's no point forcing the pH downwards if the carbonate hardness is high. Try to understand this critical fact: pH doesn't matter, hardness does. Fish (mostly) don't feel pH (though they certainly don't like rapid pH changes). What directly affects them is hardness, because this controls [a] osmoregulation and [b] the pH stability. Hard water, whether we're talking about high general or carbonate hardness, is not intrinsically a bad thing, either.>
I understand that once the KH is at a stable level, the PH will lower and not bounce back.
<No, quite the reverse. The lower the carbonate hardness, the less stable pH becomes. That's why marine aquarists worry about carbonate hardness so much. It's the "alkalinity reserve" that fixes pH. All tanks have a net tendency towards acidification; tanks with a high carbonate hardness tend to resist this extremely well between water changes, making the fish happy. Tanks with low carbonate hardness experience rapid pH drops, and this makes fish very unhappy. The art of soft water aquaria is finding ways to stabilise pH without relying on carbonate hardness. This is not easy to do! For all practical purposes, community freshwater tanks should be maintained at around 10 degrees dH and upwards of 5 degrees KH where possible.>
Is there any product/chemical/other method you could recommend?
<None. First get a better understanding of your water chemistry and the environment in your tank. For example, are the rocks calcareous? Is the substrate? Then decide if there's really any point changing the hardness, given hard water tanks are more stable environments. Livebearers (poeciliids and goodeids!), Central American cichlids, Rift Valley cichlids, rainbowfish, Goldfish, Pufferfish, gobies and brackish water fish will all prefer hard water conditions. The majority of barbs and catfish couldn't care less, and do fine in hard water, including things like Corydoras, plecs, and most hardy Asian Puntius spp. Choosing fish from this list gives you masses of scope for fun, colourful, weird, and challenging species. Since you won't be messing with water chemistry, your life is much easier, and you can do big water changes to optimise environmental conditions in the tank. A win/win situation.>
PS: RO/DI water is not really an option...
<Collecting rainwater works well if you want to keep a soft water tank. Cheap and easy, and very 'green'.>
Thanks in advance
-Jon
<Cheers, Neale.>

High ph on FW aquarium 11/23/07
Hi, I only use RO water for my 55g which is very soft, but when I check my aquarium water the reading is 7.0 to 7.2, what's wrong? My tank is planted and I am trying to raise angelfish and so far only two are doing excellent. Other fishes in the tank, tetras and one clown loach. Thank you, Edna
<Hello Edna. Why on Earth are you using just RO water in a freshwater aquarium? No fish will thrive in pure RO water; you have to "cut" it with some hard water so that it has at least some mineral content. Standard practise for community fish is to mix RO water with hard tap water to get something with around 5-10 degrees dH. Generic Angelfish from the pet store (Pterophyllum hybrids) certainly don't need particularly soft water, and even in the wild Angelfish don't come from the same very soft waters that Discus do. They're more common in the main Amazon river system rather than, say, the Rio Negro. Very soft water also experiences wild fluctuations in pH unless you're taking specific measures to prevent this, and fluctuating pH is much more harmful to a fish that a pH that doesn't "seem" good compared with what they have in the wild. In other words, Angelfish are happier at a steady pH 8.0 than at an acidic pH that keeps bouncing around. So, please have a read of the article on Soft Water Aquaria here, http://www.wetwebmedia.com/FWSubWebIndex/fwsoftness.htm . If you can tell me something about the general hardness (dH) and carbonate hardness (KH) then we can can try and find out why your pH is fluctuating. One last thing: a neutral pH at 7.0 to 7.2 is absolutely perfect for just about every common community fish except livebearers. So I'm not sure why you want to lower it, and in any case, you should never fixate on the pH; what matters is the general and carbonate hardness. Get those right, and the pH will do the right thing all by itself. Cheers, Neale.>

Re: high ph on FW aquarium 11/25/2007
Thank you Neale for replying to my e-mail and for the information about the water.
<Happy to help.>
I have a 5 in 1 test kit: Nitrate "0", Nitrite "0", Total Hardness (GH) 25, Total Alkalinity (KH) 300 and PH 8.4.
<This is the tap water, right? Very similar to what I have here in Southeast England. For most purposes, perfectly serviceable if you go with hard water fish (e.g., livebearers and rainbows) and plants (Vallisneria, Egeria, etc.). Even soft water fish like tetras, Corydoras etc will adapt just fine. But if you have RO water anyway and want to soften the water a bit, then mix 50:50 with RO water and you'll have something just about perfect. 10-12 degrees dH and 150 mg/l alkalinity is an excellent target for a wide mix of community tropicals. Plants will adapt to this very well, especially if other factors -- lighting, nutrient-rich substrate -- are taken care of properly.>
My "concern" is that live plants: Amazon swords, mongo grass, Anubias and others that I don't know the names and I keep in my tank, thrive better "in the soft side of water" (I read this somewhere).
<Some Amazon Sword species actually prefer hard water so you need to check which species you have. Most are adaptable and care much more about substrate quality and lighting. Mongo Grass is a species of Ophiopogon, and will die underwater anyway (it's a terrestrial plant) so I wouldn't bother with it at all unless you like watching plants rot. Anubias spp. are all very adaptable and will happily grow in quite brackish water, so they don't care in the least. Relatively few plants actually prefer very soft water, and once you get below 5 degrees dH, most will simply sit there looking unhappy. Something between 5-15 degrees dH is just about perfect for a wide range of aquarium plants. Do buy/borrow one of the many excellent aquarium plant books out there. Water chemistry is simply not an issue for the vast majority of them. Most plants in aquaria fail either because [a] they aren't aquatic plants to begin with, or [b] not enough light. Everything else is icing on the cake.>
So much info out there and sometime it get too high tech and overwhelming for me.
<I sympathise. One of the big problems with the Internet is that the sheer volume of information published there isn't matched by the same level of fact-checking or editing. Anyone can publish anything. So while books and magazines might seem old-fashioned, they are at least offering a high standard of information.>
Over all my aquarium looks very good and I love sitting for hours in front of my tank enjoying my "little master piece".
<Absolutely! I don't have a TV set in my house, but I have to confess to spending too much time gazing at my fish tanks just as if they were TV sets! It's very addictive.>
Thank you again, Edna.
<Cheers, Neale.>

Low pH 11/8/07
Hi,
I am having a problem raising my pH. It stays at a 6.0. The alkalinity is at 40 and the hardness is at 300. I tried the pH increase but it didn't help and am trying the proper pH 7.0, but read that it is bad for plants. I have several bamboo, a short round leaf plant that I don't know what it is and an onion bulb shaped plant. The tank has an assortment of community fish. What can I do to fix my pH and will the treatment kill the plants?
Thanks so much!
Julie
<Julie, adding chemicals like "pH Up" to raise pH is generally pointless. Those chemicals are really buffers. That is, they are designed to stabilise the pH at a certain point once you've already brought it up (or down) to that pH level. So if you have a Lake Malawi aquarium with lots of nice hard water, adding a "pH Up" product will make sure the pH stays at the 8.0 value Malawi cichlids like so well. But if your aquarium is way off base, these buffering potions will be overwhelmed. In this case, you need to sit back and look at what's going on. You aquarium has a low carbonate hardness. This means that the pH easily falls towards the acid end of the pH scale. The way to remedy this is to add carbonate hardness. There are multiple ways to do this, but the simplest is to make a mixture of equal parts bicarbonate of soda, Epsom salt and marine salt mix. Add a teaspoon to each bucket of water, and stir well. Test the carbonate hardness and pH of the water. It should be much higher. If it's too high, repeat using less of the mixture; if it's too low, repeat using more. What you want is something around 100-200 mg calcium carbonate (6-12 degrees dH, 5-10 degrees KH). This water should have a pH around 7. It will be perfect for a wide range of community tropicals, with the exception perhaps of livebearers, which like water that is more hard and has a higher pH. Tetras, barbs, Gouramis etc will all thrive under such conditions, and the biological filter and plants will also do their best. One thing: make these remedial actions slowly, changing no more than 25% of the water per day. While aiming for neutral pH, moderate hard water is ideal for the community tank, rapid changes in water chemistry can be lethal to fish. As for your plants, the "onion" is probably Crinum sp., perhaps Crinum thaianum, a lovely aquarium plant. Bamboo doesn't normally survive in aquaria, especially when kept submerged. It might survive allowed to grow out above the tank, but that's not really practical. Do be aware that many aquarium shops sell non-aquatic plants to unsuspecting fishkeepers. It's a sad state of affairs really. You need to know what plants you want, and THEN go shopping, and not go shopping and come back with a bunch of mystery plants. Good luck, Neale>

Beginner needs help, FW... set-up... pH 11/08/07
I have been reading for days on your site. I appreciate all the information, but have been unable to understand what is going on with my tank.
<Fire away!>
I have a small 10 gallon freshwater tank.
<Ah, too small for beginners in my honest opinion. Small tanks are unstable and problems spiral out of control very quickly. Advice to other beginners: start off with a 20 gallon tank if you want an "easy ride".>
I was using distilled water and had plastic plants with tetras and a guppy.
<Why? Distilled water is completely unsuitable for aquarium fish or indeed any living creature. Tap water is much the best for beginners, though dechlorinated of course before use.>
We kept the tank for about 6 months with no problems. Our guppy just died one day.
<Surprised it took that long...>
We decided we wanted to have some ghost shrimp, an algae eater some live plants. The ghost shrimp died right away.
<Not a surprise at all].>
We now understand they are not that hardy. We were told our water was soft when they tested it at the pet store. they thought we could use tap water in our area with some aquarium salt and prime.
<Sheesh. Pet store advice strikes back. Please, over the next few days remove a portion (20%) of the water in your tank and replace with dechlorinated tap water. Do not add salt. If your local tap water is soft and acidic, then don't keep fish that need hard and alkaline water (such as guppies). Stick with genuine soft water fish, such as tetras.>
Our ph seems to stay around 7.4 no matter what we do.
<That's a fine pH for most fish. And a stable pH is a GOOD thing.>
We added some sea shells as told to.
<Why?>
We drain and add every week and a half to two weeks. We have been doing about the 20%.
<Change 50% per week. This is the cheapest and easiest way to keep a happy collection of fish. Few problems can't be solved by dilution.>
Our tank looks beautiful, water looks clear, we ended up with 2 snails on the plants.
<Water clarity is irrelevant in keeping fish. You can have clear water that kills fish overnight, because ammonia (for example) is invisible. By contrast the water most fish live in looks like milky coffee and yet they (obviously) thrive.>
the water was running a little warm (80-82 degrees) but we changed our incandescent bulbs out for the fluorescent.
<Good. Very few fish like water this warm, and some will have dramatically shorter lives when kept thus. Aim for 25C/77F; no higher.>
There are some very strange tiny hair like, things for lack of a better word, on the glass of the tank. They are tiny, barely can see them attached with one piece with like three hair like things off them.
<If static and whitish, that's mould or bacteria. If static and green, it's algae. If mobile and whitish, then nematodes. Not problematic in themselves, but potential clues to other issues.>
Also we have sand in our tank instead of gravel.
<Sand is fine, just keep it clean.>
Do you have any advice for us?
<Read an aquarium book or this web site. Relying on local fish store advice can be tricky. Shops want to sell you stuff, and largely don't care if your fish live 6 weeks or 6 years, so long as you come back and buy more fish and other products. Educating yourself is the key to solving your own problems, and using your pet store as a resource for essential purchases.>
What do you think these little things are? Also, one of my tetras looks a little stressed. His stripe does not look right like he has faded.
<Fish do lose colour when stress. Water quality, water chemistry, diet, bullying can all be factors. Need more data.>
I am worried I have done something wrong. I did notice you said in many articles not to overfeed. Our fish eat all the food at the top of the water when we feed. We are very careful about that.
<Very good.>
Is my ph really messed up for another reason?
<A pH above 7.0 can be caused by two main things. One is good: calcium carbonate in the water. This raises the carbonate hardness (measured with a KH test kit). Guppies and other livebearers love carbonate hardness, and carbonate hardness also buffers the pH in the tank, keeping it steady. The bad source of a pH above 7.0 is ammonia. So test for ammonia (or have the pet store do it for you). Ammonia is a severe poison.>
Does the sand really mess up our tank?
<No. But not all sand is equally good. Some sand is calcareous (e.g., coral sand) and will raise carbonate hardness and pH; other sand is non-calcareous (e.g., silica sand) and has no effect on water chemistry.>
It seems like with plants we are reading a lot about gravel.
<Depends on the plants. Non-rooted plants like Java fern and Anubias couldn't care less, and actually get unhappy (die) if stuck in the sand or gravel at all. Most plants prefer sand to gravel, because the slightly anaerobic conditions in the sand shift mineral ions into their reduced (as opposed to oxidised) states, making them easier to absorb. By itself, plain gravel or plain sand aren't really suitable for growing plants anyway, no more than land plants would grow if you stuck them in a flower pot filled with gravel or sand. To get good plant growth, you need to augment the substrate with something else, like aquarium soil or laterite, that contains minerals like iron.>
Thanks for all your help.
L
<Hope this helps, Neale>

pH Level While Using Red Sea Floralbase 11/07/07
Hi,
I have recently set up a new 72gal FW tank. I have had water in it, Rena xp3 filter, heater, and Corallife 65watt x2 for lights. I presently have 15 goldfish in it to help with the cycling.
<<A poor idea. Too much stress and likelihood of parasitic infestation... RMF>>
My ph level has been at 6.0 from the start. I am using red sea Floralbase, that's all, as I have a planted tank. I am wondering how to raise the PH level to at least 7.0 for the types of fish I want (I have a 10gal that has been established for 2 years now & I would like to take those fish and move them over to the new one, that PH has been 7.0 - the fish in the 10gal is neon tetra, black skirt tetra, 2 Danios and 1 Chinese algae eater). Is there some sort of PH up that I can use safely? I do have several kinds of plants. My ammonia, nitrites and nitrates are all within the proper range & are great.
Thanks
Kim
<Hello Kim. Two things here. Firstly, what sort of fish do you want to keep? An acidic pH of 6.0 is actually very good for a wide range of species. Most South American fish will thrive here, as will most of the fish from Southeast Asia. Secondly, you need to clear up the difference between pH and hardness in your head. Fish don't "feel" pH directly and don't really care about it all that much; what matters is how much mineral content the water has, because this is what has an impact on osmoregulation (how they balance salt and water in their bodies). So, what you want to check first is the hardness of your water now, and the preferred hardness of the fish you want to keep. I'm guessing your water is quite soft (i.e., a low hardness around 5 degrees dH). That's fine for tetras, angelfish, Gouramis etc. But if you want to keep livebearers or Rainbowfish, they need a higher level of hardness, at least 10 degrees dH and ideally well above that for livebearers especially. Once you take care of hardness, then the pH will adjust itself pretty well automatically. Hard water tends to have a high pH, and that high pH is pretty stable. There are various ways to raise the hardness. The simplest is to incorporate some calcareous material into the filter. Crushed coral is one such medium. As the water washes past, the coral dissolves, raising the hardness. Periodically you clean the coral to wash away slime that coats it, and maybe once a year replace it with a bunch of new coral. There are other methods too; any aquarium book should discuss them, but if you want some more ideas, let me know. Cheers, Neale.>

High ph and low alkalinity, Discus sys. 10/22/07
Hello,
<Hi there>
I am a long time aquarium keeper who has been quite lucky over the years and just let my tank be whatever way it balanced itself to be and have kept a general variety of fish without any problems or turmoil.
That is until I decided that I want to keep discus. In talking to my LFS about doing this it was recommended that I change some things within my tank before purchasing discus otherwise I would just be wasting my money and their lives.
<Let's see>
All things recommended have been accomplished over the past year (not without much appreciated help from you guys I might add) except one.
The main and most troubling change is "buffering-in" a lower pH. I have done everything you have recommended; I changed to RO water to solve the liquid rock tap water problem; I lowered my KH to 3dK; I incorporated several pieces of driftwood; I began religiously changing out 20% of the water in the tank every week; etc, but guess what? pH is still 7.4-7.6.
<This may not be an issue... Are the Discus you keep tank-bred and raised (i.e. not wild-caught?)... If so, this pH range is likely fine>
I did try phosphate buffers which did a great job of keeping my pH where I want it between 6.5 and 6.8, but caused an algae bloom, and dropped the KH to zero, so no more phosphates for me thanks.
I have tried several other things to bring down the pH as well, including allowing the detritus to build up in the gravel
<Mmm, not recommended>
which just brought about a blue-green algae problem and I have tried non phosphate acid buffer which only chips away at the KH before disappearing and allowing the pH to rise back up.
<Yes>
So this is where I am and I hope that you can help. I use RO water and add back the minerals using Kent's RO right. I add 1.5 tsp to 15 gal, which results in a TDS reading of 170ppm on an electronic probe, and an undetectable reading on a calcium/magnesium GH titration test kit ( I don't know why GH is so low with this product, nor do I even know if I should be concerned with it since the TDS reading is high enough). I add KH by adding bicarb to attain a KH reading of 4dK. Then I use this water for my changes.
<Mmm, depending on the make-up (GH, KH) of your source water, I'd likely give up the Kent's product and just add/blend some of this in with the RO>
I have heard much on alkalinity and carbonates to buffer against a drop in pH, but what about buffering against a rise in pH?
<Is a/the same concept... a buffer "holds" or resists change in both directions... depending on the "trend" in captive systems (most all are decidedly reductive, as in reduction/oxidation... OILRIG, "oxidation is losing, reduction is gaining...." electrons... Acids are proton donors, electron acceptors... basic (not a pun) chemistry... Tanks tend to "go acidic" with time... resultant from feeding, decomposition processes, crowding...>
What "stable" chemicals, and acidity buffering tests etc can be employed in the fight against a rising pH?
<First, the discovery of alkaline/alkalinity sources... Likely substrate here... perhaps more pre-eminently, the checking of your test gear as well....>
I already have my KH as low as anyone would recommend.
Thank you
SL
<Again, really... I would NOT be concerned with the mid 7's pH you state... IS fine, esp. if the Symphysodon have been captive-produced... I would suggest another 20% change of water (twice per week) to lower metabolites... Much more of a likely issue than pH effects. Do please read this excellent piece by NealeM here: http://www.wetwebmedia.com/FWSubWebIndex/fwhardness.htm
and the linked files above. Bob Fenner>

High Freshwater Alkalinity – 10/01/07
I work at a LFS, and lately, we've been having a significant problem with our 900gallon freshwater system and super high alkalinity. We have done massive water changes with both tap and R/O water in attempts to lower it, but to no avail. We have even tried using club soda to bring it down!
The pH is staying at a consistent 6.9-7.0. We have drained each of the 36 tanks, and nothing seems to be lowering the alkalinity. Please, if you have any suggestions as to what may be the problem, I'm all ears! The tap water has almost no alkalinity at all, so something, somewhere, in the system is keeping it high. Thanks in advance for any help you can give!
-Erica
<Hello Erica. Assuming there's nothing in an aquarium dissolving into the water, the water chemistry in a freshwater tank should be approximately similar to that of the tap water. Regular water changes (say, 50% weekly) should dilute the background acidification that happens as organic material (such as plant leaves and bogwood) decays. So, there's really only two things that can be happening here. Either there's something in the tank that's rapidly changing the water chemistry, or your test kit isn't working. I can't see what else could explain this. Obvious sources of alkalinity in freshwater tanks include the substrate (coral sand for example), limestone rockwork, calcareous filter media, and so on. Now, we're talking about alkalinity, but specifically what are the test results? Marine aquarists use a number of methods of measuring alkalinity, such as milliequivalents per litre, but in freshwater tanks the only measurement widely used is degrees of carbonate hardness (KH). Is that what you mean? Let me have the number and measuring scale, and we can discuss further. Finally, always bear in mind that rapidly changing water chemistry -- even from "bad" to "good" -- is potentially dangerous to your fish. Virtually all freshwater fish can adapt to slow changes, and will prosper under conditions well outside those they enjoy in the wild, provided they are given time to adapt. If all else fails, take the "nuclear option" -- strip the tank down, remove all the substrate, replace all the filter media, and re-cycle the aquarium. Assuming you do this properly, the new tank should share the same water chemistry as your local water supply. Cheers, Neale>

Can't win Alkaline/Acid battle freshwater... – 09/29/07
We have lost 2 fish in the last week and believe it's high pH and/or high Alkalinity.
<Unlikely. Most standard tropicals will adapt to fairly high pH levels, especially if adapted over time. Better still, you can easily pick species -- such as livebearers -- that thrive under such conditions.>
Our store guy said our tank's pH "is as high as a saltwater tank (7.8)" It is 8.5 now.
<That is somewhat high. But even 8.0 is well within the tolerances of things like Corydoras and domesticated angelfish.>
So he's caused us some concern as we cannot get the alkaline or acidity measurements to go down.
<You should really fixate on the pH. It's a red herring. Find out what the general hardness (dH) and carbonate hardness (KH) are, because these are the critical water chemistry values. Then do an ammonia test -- ammonia will raise pH dramatically. Ball park figures? For standard tropicals, anything up to 20 degrees dH and 10 degrees KH are fine. Above 25 degrees dH, 15 degrees KH you want to concentrate on species that like hardwater: livebearers, Central Americans, Rift Valley cichlids, brackish water fish, etc.>
Both are very high on the test strips we use. (I thought this was impossible?)
<Give me NUMBERS, not your opinion!>
About our tank, it's a 10 gallon, freshwater. We have no plants, coral, nothing.
<What's the water right out the tap? In a reasonably stocked aquarium where you perform water changes on a weekly basis taking out 50% of the water at a time, the water chemistry in the aquarium should be as close as Dammit to the water out the tap.>
Has a filter/aeration system and fluorescent lighting.
<OK, but if the filter is underpowered, you'll have ammonia too. That'll raise the pH very quickly.>
Everything I found on WWM seemed to say 8 to 8.5 is normal.
<Define "normal". As I say, a properly maintained aquarium should have water chemistry essentially identical to your local water supply.>
What should we do?
<First, sit back and take stock. Water doesn't suddenly change water chemistry for no reason. If you have hard, alkaline water out the tap, then nothing you can easily do will change that. Buy hardwater fishes, and they'll thrive, and you won't have to worry about anything. If the water is neutral and not too hard out the tap, then your very high pH is coming from somewhere. Ammonia is the common explanation -- either poor filtration, or from chloramine used to treat the water by your local water board. Chloramine breaks into ammonia and chlorine when treated with traditional dechlorinators, so check your dechlorinator removes chloramine AS WELL AS chlorine. Not all do.>
Tank is my ten year-old son's and he is becoming discouraged
enough to give up aquarium which I think has been good for bldg
responsibility.
<Teach your son that things go wrong whatever you're doing. The way over these hurdles is to study the problem, try out ideas, ask for help, and then move forward.>
So I'm mostly confused at this point.
Thanks for your great website by the way.
Eric Jensen
<Get back to me with water chemistry measurements -- dH, KH, and ammonia -- and we can perhaps solve this for you. Cheers, Neale>

Filters and pH questions 9/26/07
Our tap water here in Oregon is very very soft (dH 2-3), but they use sodium hydroxide to raise the pH to 7.7 so as not to rust pipes.
<What a horrible set of water conditions... very soft, but slightly alkaline. Nothing much really likes these conditions.>
It quickly drops to 7.2 or so in the tank.
<Well that's lucky.>
Is this OK for cardinal tetras, Apistogramma, loricariids? Soft water Amazon fish seem to be doing well.
<I'd be tempted to add a certain amount of a pH-down product to reduce the pH to exactly 7, while increasing its buffering capacity. On its own, very soft water tends to fluctuate in pH quite a lot. This is not good. Standard pH-down products (usually sold as bottles, and you add a bit to each bucket of water just like dechlorinator) stabilizes the pH at some value. In hard water they're a bit of a waste of time and money, but in very soft water such buffering solutions (as they're called) can be very helpful.>
Also, I have a Rena Filstar filter. Has the standard 2 layers of foam, a bag of carbon (bio chem zorb) and a layer of micro fleece pads. Was thinking of replacing either one of the layers of foam or the carbon with either some ceramic biomedia or keta peat nuggets.
<Bin the carbon. Total waste of space. In very soft water, the filter bacteria tend to be less happy than in hard water (they like hard, alkaline water best of all, and stop working completely below pH 6). So concentrate on adding as much biological media as possible to get the best water quality. Choose whatever according to your budget and preferences. The main thing is that the filter should have not less than 4x the volume of the tank in turnover per hour. In other words, for a 100 litre tank, the filter must have a turnover of 400 litres per hour.>
That's a lot of foam sponge, and maybe the carbon is not so necessary. The peat would lower that NaOH induced pH.
<Don't use peat. Peat is wonderful stuff in aquaria if you know precisely and absolutely what you're doing. But peat can rapidly change the pH and its results are completely unpredictable. In very soft water with practically zero buffering capacity, you could easily drop the pH from 7.2 to 6.0 overnight if you added too much, and this would kill your fish. Instead, use the buffering solution mentioned above, following the instructions on the bottle, and performing pH tests every day or two at first until you get a sense of how pH varies in the tank. What you're after is 7.0 day in, day out.>
What do you think?
<Messing with pH is something a lot of aquarists get into trouble over. There's a very good argument for not thinking about pH at all, and focusing instead on general and carbonate hardness. Both of these have a much bigger impact on the fish. With your very soft water, the KH value is likely to be very low, and as a result water chemistry stability practically non-existent. So your job is to stabilise water chemistry. Adding buffering solutions to the water will do this. This becomes more important the more fish you add, because the loading of the tank is positively correlated to water chemistry stability as well. In other words, heavily stocked tanks experience a drop in pH more quickly than the same tank would if lightly stocked (a process called acidification). So, move slowly, research the water chemistry topics here at WWM, and measure pH regularly to check that acidification isn't getting serious. Cheers, Neale>

High ph, hard water-Oscar – 09/14/07
Dearest Crew,
I have extremely hard water and have 5 freshwater tanks. I don't completely trust dipsticks but I think this one is probably reasonably accurate. It says total hardness (GH) is 300 ppm and total alkalinity (KH) is barely under 300 ppm. We have well water with no chlorine or anything. I took it all with a grain of salt until I tried softening & lowering the ph with buckets of test water. I didn't want to put anything in the tanks until I knew what the end results of my bucket tests were. I've been reading extensively the past 4 wks on WWW about ph (something I never understood until I found your crew). The more I read the more concerned I became. I try so hard to feed the right food for each fish, give them plenty of room, keep ammonia, nitrites and nitrates all always '0' by quick 3-4% daily water changes. I want to take care of them right because they're my little charges and they only have me to do it.
My 'newest' fish is my now 4" red Oscar. I've him about 2
months. Lord, I love that wiggly little beggar fish. I care very much for my Severum, Goldfish & Blood Parrots but I'm completely enthralled with this little Oscar. I was lulled all these years by the idea that "stable PH is better than unstable proper PH" but now I'm wondering if I shouldn't have been so complacent.
After finally understanding PH & alkalinity I'm worried about my Oscar because I adore him so and my Severum who needs a considerably lower ph. The ph of my 4 day old aerated water
is 8 to 8.2, the ph in the tanks runs about the same according to my Aquarium Pharmaceuticals liquid test tube kit.
I use pea gravel and inert smooth aquarium gravel in the tanks I'm concerned about, old driftwood, no limestone or dissolving rocks of any kind.
I used a 10 gal tub of the aged hard water and put a big handful of peat moss tied in nylon with a bubbler. It's been 2 days now and still at 8.2. I left the peat moss in there and added the recommended amount of "Beckett PH Lower" to it. It says it has 15% citrus acid. The pH immediately dropped to 7 but after just 8 hrs it had already risen back up to 8. That's the reason I tend to believe the test even though it was a dipstick test. This water is well buffered, I just wish it was buffered at 6-7 ph. It's not about to give up and let go of the high ph for any length of time. I can't subject fish to these swings, obviously.
Do you think an 8 to 8.2 ph is far too high for my Oscar? (I know it is for the Severum). Your Oscar facts said "Freshwater: pH range: 6.0 - 8.0; dH range: 5.0 - 19.0 was acceptable for Oscars. Yet all the FAQ's always say they need 6-7 ph and medium water. If all other factors in his care are optimal, am I worrying too much or worrying for good reason? HITH disease scares me badly and I want to avoid it at all costs. I don't want to shorten their lives in any way.
I read several of (mainly) Chuck's references to mixing 80% distilled water with 20% tap water along with leaving peat moss in the tank. That sounds like something I could easily do with no
trouble at all if distilled is safe to use. If it were only my 45 gal Severum tank I could also just as easily get water from my brother's house, no big deal. But my Oscar now has a 90 gal tank and I've decided on a 125 gal long tank the 1st of the year. That's alot of water to be dragging home for water changes. If you think the situation is dire enough I'll do research on an RO unit if I need to. I also worry that if something happens to me or I end up in the hospital and my husband had to do water changes he'd never be able to understand complicated water changes. He could easily do them by aging our plain tap water though (with me shouting orders from my hospital bed-ha!)
Could you please let me know if my ph is unacceptable for my Oscar? If it is, I'll do whatever I can to change it the right way. If it's not that big of a concern I can quit worrying so much about it.
It seems far too many people start mixing, changing & switching with the "If it ain't broke, fix it till it is!" mindset and I don't want to do that.
I apologize for the length of this email. What you're doing for the aquarium hobby is above and beyond the call of duty. I'm so thankful for your website.
Sincerely,
Mitzi
<Mitzi, the first thing to understand is pH is not important. Fish don't feel pH. What they react to is something called total dissolved solids, or TDS. It just so happens that high TDS tends to go along with alkaline pH and low TDS with acid pH. But because pH is "easy" to understand, and TDS is "difficult" to understand, aquarists often focus on pH instead of TDS. The analogy is IQ. People often think a high IQ means someone is smarter than someone with a lower IQ, but the reality is that all IQ measures is someone's ability to succeed at IQ tests. There are lots of very skilled, capable people like surgeons and artists and engineers who don't have particularly high IQ levels, and lots of people with high IQs that do incredibly dumb things and don't have particularly impressive careers. If you want to change the water chemistry in an aquarium, what you need to focus on is the TDS, not the pH. Adding magic potions that raise and lower pH is really wasting time and money. Yes, you can add pH-down products to an aquarium where the water has a high TDS level. And the pH may well become acidic for a while. But what you're actually doing is changing one set of mineral salts to another (through an acid-base reaction). You aren't removing those mineral salts, so you aren't softening the water in any meaningful way. If it really was that simple, people wouldn't be spending $100s on reverse-osmosis water softeners! If you genuinely want to put a soft water fish into a soft water aquarium, you have two options: use RO water or use rainwater. I do the latter, because its cheap and easy, but RO has the advantages of convenience and perhaps greater safety if you live in potentially polluted areas. Like Chuck suggests, I mix rainwater with hard tap water to get the water chemistry I want. But adding pH-down chemicals to the water IS NOT an option, so don't bother. Now, there is some misunderstanding about the water requirements for Astronotus ocellatus. Wild fish are found in a variety of habitats with both soft and moderately hard water. They have also become established outside their natural range (e.g., Florida) where they are living perfectly well in hard, alkaline water. According to Fishbase, which is based on wild, not aquarium, fish, Astronotus ocellatus has a hardness range of 5-19 degrees dH, which places your hard water well within its tolerances. I can also mention at this point that Oscars are routinely kept and bred in very hard, very alkaline water here in Southern England. Wild Astronotus ocellatus may be a little more fussy, but the aquarium strains aren't at all fussed. Looking at your other fish: Severums are found in a range of waters including brackish water, so they don't care. Blood parrots are some kind of hybrid of Central American cichlids, so they actually need hard/alkaline water and tend to be sickly went kept otherwise. Goldfish prefer hard/alkaline water as well. As I've said many, MANY times most fish will adapt fine to a range of water chemistry values -- what matters is stability. In fact, very few soft water fish fail to adapt to hard water; the problems are usually adapting hard water fish (like livebearers and Mbuna) to soft water conditions -- they usually get plagued with fungus or simply die. Changing water chemistry is something to do ONLY if you want to breed a particular species, AND even then ONLY once you are satisfied you understand what TDS, KH and GH are all about and how they interact with the conditions in the tank. If you don't understand them, then don't try and change them. For routine maintenance in display aquaria, stick with the water you have and concentrate on water QUALITY. So, in short, put the bottle of pH-down potion away, and just enjoy your fish. Cheers, Neale>

Re: High ph, hard water-Oscar – 09/14/07
Neale (and WWM),
Thank you thank you for the super fast informative answer! You've really put my mind at ease with such a complete answer. I've no doubt your response will help many people. What a relief, truly. They've all done so well, grown so fast and been consistently active for several years, it was hard to wrap my mind around the possibility that the hard/alkaline water was hurting them. But that's subjective because my own fish are all I have to compare to on a day to day basis. I feel very much relieved after your answer. Messing with their pH is something I certainly didn't want to have to do.
I've got dogs, cats, pet sheep, a pet rat, a dove and my other fish but this little $6 Oscar from PetSmart has given me more laughs and relaxation than anything else money could buy. Such intelligence and personality they have! I think doctors should prescribe an Oscar instead of Prozac and they'd have better results :-)
Thank you again for your words.
Mitzi
<Mitzi, glad to be of help. Yes, people do get worked into a lather over water chemistry, but the bottom line is that with freshwater fish at least it is relatively unimportant. Oscars are wonderful fish, and seem truly to have a genuine affection for human companions. There are many stories about people teaching them tricks and games. And yes, the therapeutic value of fish tanks is quite well known. They seem to slow people's heart rates and generally reduce stress. And simply working with animals and plants is just plain good for the soul. So enjoy your animals, and good luck. Neale>

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