pH keeps dropping to 6.4 no matter what I do.

[fluvial_shell]

Hi. I'm new here and signed up because no fish store in my area can seem to help me. Basically, I've got the exact opposite problem from the "proper pH" thread -- I can't keep my pH around 7. It keeps dropping to 6.4-6.6. I had a couple large snails that I loved, and one of them has died now because of this. The other one is struggling. The strange thing is that our municipal water is around 7.2. I don't know how hard it is -- apparently, not very! I changed the water yesterday and tested around 7.0. Great. This morning I checked it and it's right back down to 6.4. I used about 2 tablespoons of Sodium Bicarb to raise it back to 7.0, but I've done this before, and it's going to be back to 6.4 tomorrow, I guarantee. I'm about to totally change out my gravel to a limestone mix, but it doesn't seem right. Is my log causing this problem? Any thoughts? Thanks for your help!

My tank details are below:

28 gal. w/ Whisper Power Filter 40. Carbon BioBag installed and changed every 2-3 weeks. 1/2-3/4 water changes every week w/ gravel vacuum and capful of Prime. Coarse silicate stones and gravel. I have a large slate-mounted log with two live plants growing on it. Community are black and neon tetras, large pleco, and several livebearers. Down to one snail now :(

Oh yeah, does anyone know about kits for testing Hardness? That might be useful.

[Sasquatch]

Did you let the log soak in a separate container first? Is your water colored? Your log could be causing the problem, but I don't think it's enough to cause such a huge change in pH.

The silicate substrate could also acidify a little bit. But again, I don't think it would be anything that radical.

The basic question you have to ask yourself is why do you want your pH at 7? None of the fish you mention need particularly alkaline water and tetras actually like it on the acidic side. Basically, decide if pH 7 (and all the work that would entail) is more important to you than a stable pH . Also, pH 6.4 isn't particularly acidic.

I'd let it run at pH 6.4 a while and see how it goes. Keep an eye on it, test pH daily. A hardness test kit could also come in handy, but if you're pH is changing that fast, you probably don't have much hardness.

By the way, I sympathise. I have the exact opposite problem, no matter what I do, my pH goes up to around pH8.2-8.4. Our tap water is around 7.4. After some testing we found out that our gravel has limestone/shells in it. But we do weekly water changes and it stays around pH8, which is fine for our platies and the catfish seems to tolerate it well (at least for the two days he's been in the tank!).

Best of luck and I hope you find the cause.

[cocoa_pleco]

Most of your fish like the 6.0-7.5 ph range, so youre fine. If the only thing being affected is the snail, will a lfs take him?

[fluvial_shell]

Thanks for the reply. I agree that most of my fish are pretty tolerant in a range of pH. Snails, however, are not. Acid and shell-building don't go well together. Also, I was trying to have a go with Black Mollies and having a miserable time of it. My reference (Aquarium Fish by Schliewen) says that Black Mollies need 7.5 to 8.5. So I figure that 6.5 would contribute to their stress, and I've had three out of 4 die (3 different batches, so not a genetic problem).

I'm not sure I agree about 6.4 not being very acidic. Technically speaking, since pH is a logarithmic scale, 6.4 is really 6 times more acidic than 7.0. It's not extreme blackwater (4 or 5), but long-term improper pH cannot be good for fish who need 7 or above. What you say about pH stability is interesting to me, though. Is a stable but improper pH better than an instable but occasionally proper pH? Now that's the question! :) It sounds like you're saying that stable is better, regardless.

As far as the wood in the tank, it was clean and sand-blasted when I got it. My tank is crystal clear, although it comes out a bit yellow after water changes (urea, I assume). My tank was right on target pH wise for the first few months I had it. Then I tried this 7.0 pH buffer from the store, and it turned out that it was buffering it to 6.4 (bad lot of buffer, salesman said -- we tested it on fresh tap water: 6.4, goshdarnit). I haven't been able to keep the pH up since. After dozens of water changes, I would think that bad buffer would be long diluted, and now I'm just left shrugging my shoulders.

You ask a good question. Why do I care? Maybe I should forget the snails and just let my tank be what it is and get fish that match the water conditions. Part of it is pure stubborness, and the other part is just wanting to know what's going on. I realize the irony, however, for so many people with hard water. Wanna swap tanks?! ;)

[Chrona]

Try taking the log out. I think it's still leeching acid into the water and neutralizing the alkaline buffer you put in.

[fluvial_shell]

6.4 is actually 4 times more acidic than 7.0. 10^(-6.4) / 10^(-7) = 3.98
We're not talking an HCl or H2SO4 solution here, but the log scale makes pH changes seem less than they are. Now, how much do the fish feel that change? Well, that is the question! :)

[Chrona]

6.4 is actually 4 times more acidic than 7.0. 10^(-6.4) / 10^(-7) = 3.98
We're not talking an HCl or H2SO4 solution here, but the log scale makes pH changes seem less than they are. Now, how much do the fish feel that change? Well, that is the question! :)

It depends on how fast the change occurs. I forgot to add acid buffer to my hard water when doing a water change the other day, and my pH shot up from like 6.4 to 7.2 within a few hours. My fish are doing fine, but then again, they've always been a rowdy bunch that don't get sick.

[cocoa_pleco]

Driftwood easily leeches acid into tanks

[Lady Hobbs]

Wood will soften the water for a period of time but I doubt it will drop the pH from 7.2 - 6.4. I also suspect the type of substrate being used as this is a rather large drop.

[cocoa_pleco]

could be the substrate

[Sasquatch]

Thanks for the reply. I agree that most of my fish are pretty tolerant in a range of pH. Snails, however, are not. Acid and shell-building don't go well together. Also, I was trying to have a go with Black Mollies and having a miserable time of it. My reference (Aquarium Fish by Schliewen) says that Black Mollies need 7.5 to 8.5. So I figure that 6.5 would contribute to their stress, and I've had three out of 4 die (3 different batches, so not a genetic problem).

I'm not sure I agree about 6.4 not being very acidic. Technically speaking, since pH is a logarithmic scale, 6.4 is really 6 times more acidic than 7.0. It's not extreme blackwater (4 or 5), but long-term improper pH cannot be good for fish who need 7 or above. What you say about pH stability is interesting to me, though. Is a stable but improper pH better than an instable but occasionally proper pH? Now that's the question! :) It sounds like you're saying that stable is better, regardless.

As far as the wood in the tank, it was clean and sand-blasted when I got it. My tank is crystal clear, although it comes out a bit yellow after water changes (urea, I assume). My tank was right on target pH wise for the first few months I had it. Then I tried this 7.0 pH buffer from the store, and it turned out that it was buffering it to 6.4 (bad lot of buffer, salesman said -- we tested it on fresh tap water: 6.4, goshdarnit). I haven't been able to keep the pH up since. After dozens of water changes, I would think that bad buffer would be long diluted, and now I'm just left shrugging my shoulders.

You ask a good question. Why do I care? Maybe I should forget the snails and just let my tank be what it is and get fish that match the water conditions. Part of it is pure stubborness, and the other part is just wanting to know what's going on. I realize the irony, however, for so many people with hard water. Wanna swap tanks?! ;)

Well the bad batch of pH buffer could be your problem. Same thing as with our gravel, it was suppose to be non-alkaline, but it turns out it has limestone in it. Water changes should help, but if you've already done dozens, I'd have to shrug my shoulders too. Find yourself a hardness test and check the aquarium water and your water change water.

Another question. You mention that you water goes yellow when you do water changes. What makes you assume it's urea? What is the source of the water for the water changes? Well water, municipal, RO?

As for pH 6.4 being acidic. Strictly speaking yes, it's lower than 7.0. But in my neck of the woods (Northern Ontario) most of the lakes are around that pH and I've seen snails as big as golfballs and crayfish are far from rare. I wouldn't recommend keeping African Cichlids, but Mollies should be ok. Take for example my catfish, it's listed for a pH range of 6-7.5, right now he's at pH 8.0 and he's doing fine.

[Chrona]

Most fish can adapt to a wide range of pH's, so the actual pH is not so much a concern as is the stability of it, as well as how slowly you acclimate them. For instance, my tetras all did ok in my really hard well water with a pH of 7.8

[Nautilus291]

try adding an air wand to your tank, more oxygen in the tank raises your ph.

[Chrona]

try adding an air wand to your tank, more oxygen in the tank raises your ph.

I thought it was because the disturbance causes the release of more CO2 from the water? Or does it have to do with the bacteria?

[Nautilus291]

you might be right. I just read somewhere that adding a bubble wand raises your ph and adding co2 to your tank will lower it.

[Chrona]

Thanks for the reply. I agree that most of my fish are pretty tolerant in a range of pH. Snails, however, are not. Acid and shell-building don't go well together. Also, I was trying to have a go with Black Mollies and having a miserable time of it. My reference (Aquarium Fish by Schliewen) says that Black Mollies need 7.5 to 8.5. So I figure that 6.5 would contribute to their stress, and I've had three out of 4 die (3 different batches, so not a genetic problem).



As for the black mollies, they are actually a brackish water fish, so you need to add at least some salt to the aquarium, which may not go too well with some of the other fish

http://www.liveaquaria.com/product/prod_display.cfm?pcatid=2089&N=0

I think you just need to spend more time acclimating them, as the fish store may have them in a brackish tank.

[kimmers318]

Oh if only I had your bad luck with soft water!! But, since you are concerned, I will have to agree, a stable ph is much better than a constantly fluctuating ph for your fish.
As for the snail, I believe there are things you can do to help him with his shell. I am not real experienced here since I only breed snails as food for puffers:hmm3grin2orange: but I do believe I have read that things like cuttle bones (for birds) and calcium supplements can help with the shells. Do some research and see what you can come up with.

[SouthernGal0682]

I am certainly no expert here, but the yellowing of the water kinda sounds like the tanins that come out of drift wood. The only reason I know is I am soaking a large piece right now and have been for 2 weeks. The water yellowed a lot the first time. Then after a few water changes it only looked yellow when I first added new water and would disappear after a few hours. I dunno...Just a thought.

[cartmanis]

Had the opposite problem at my last place. Water was very hard. We had a water softener, but it seemed to only affect the Gh not the Kh of the water for hardness. and my PH was fairly high, closing in on 8. I played with ph down and such, but never found it very successful.

My guess is, you water lacks Kh and will not maintain the ph and keep going back down to where it started from. Others may have had better luck with these products, but I never did. One would suppose you could find a rock or other decoration that would leech the minerals into the water to increase the hardness, which would probably allow it to increase the ph more successfully, but no experience there to help.