Ph Of 8

[littlest]

I've always had pH of 7 from the tap and in my tank. I haven't tested my tank water in a long while because the tank was fully cycled but then only had shrimp in. I just tested (ammonia, nitrite, nitrate,pH) because I might be adding a couple of fish tomorrow and wanted to check all was OK.
ammonia 0
nitrite 0
nitrate ~20

pH 8.

I tested the tap water and the pH was around 7.4. I've never had a difference between pH from tap and tank, so not sure what to do. Presumably this means it is bad to do large water changes? I normally do around a third, because its a small tank anyway. So what is the largest water change I should do if I have pH difference of 0.6?

And any ideas why my pH in my tank has gone up so much? I have bogwood (I thought that lowered pH if anything), slate, normal gravel, plants, one ornament. The tank isn't treated with anything other than Prime to dechlorinate.

oh and these are the fish I am thinking of getting (only one type of the following):
endlers
moquito fish
spotted rasboras
sparkling gouramis.

would any of the above fish have problems with a pH of 8?

 

[TribeOfShroom]

Sounds like the same mystery that I have in my betta breeding tank.

Tap water PH 7

Tank PH 8, although it's been 7 up until after the spawn.. so I'm kinda looking at the food because no chemicals etc have gone in there. It's a completely bare tank apart from filter, heater and a bit of hornwort tis very confusing.

You may find that your gravel may have soft rock in it. Not all gravels have this type of stone removed. That or something else is making your PH rise. You are correct about the bogwood though and I'll agree that I also would have thought that would stop your PH rising.

I'm currently doing daily water changes to bring the PH down. But only by 0.2 (roughly) each time.

 

[littlest]

so if I have a pH difference of 0.6, and I change a third of the water, would that bring the pH down by 0.2? not sure how that works OK. is a 0.2 change safe for the fish (when I add them)?

it is a bit of a mystery. Having only 3 amano shrimp I very rarely feed them anyway (they got algae). The gravel has been in the tank from the start, so it seems strange that it would only just be having an effect.

Can't think what else I've changed. Oh, I added an airstone, any way that could make a difference (it is rarely on but I don't if the material could have affected pH?).

weirdness. Normally I thought if pH was unstable it was more likely to drop than increase (just the impression I got from posts).
I don't have tests for hardness or anything, but I live in London, so presumably pretty hard water.

 

[TribeOfShroom]

so if I have a pH difference of 0.6, and I change a third of the water, would that bring the pH down by 0.2? not sure how that works OK. is a 0.2 change safe for the fish (when I add them)?

I'm not sure how much water you have to change, but I have 40L in the breeding tank. From a 10L water change my PH drops by 0.2/0.3 In regards to how much of a change is safe for fish, again I'm not sure. I've read on here that fish can tolerate ph movement if the KH is stable, but don't quote me on that.

 

[backtotropical]

so if I have a pH difference of 0.6, and I change a third of the water, would that bring the pH down by 0.2?

In theory that's how it works, but in reality it depends on your kH (how hard the water is).

The kH would have to be 0 for it to work like you suggested, so in practice, your 1/3 water change might only change pH by 0.05, if at all.

I wouldn't worry about it too much at all TBH. I would be quite confident that you could do a 50% change with no problems.

 

[Miss Wiggle]

re the bogwood, bogwood only leaches into the water for a set period of time after that it neutralises. so it could be that the bogwood was keeping the pH lower before but has stopped reacting now which is why the pH has risen. must be something else in the tank that's raising it, most likely the gravel.

 

[littlest]

thanks for that backtotropical. Like I said I don't know my kH, but I know London water is very hard (I'm presuming hard water = high kH).

Miss Wiggle - interesting theory. That could make sense actually.

 

[backtotropical]

thanks for that backtotropical. Like I said I don't know my kH, but I know London water is very hard (I'm presuming hard water = high kH).

Yes that is spot on. kH is a measure of hardness (usually called carbonate hardness). London water is very hard, and that strengthens my previous comments about not worrying. Knowing now you live in London, i wouldn't worry about pH fluctuations at all, regardless of water changes, as your water will be hard enough to fight against fluctuations.

In fact, you'd have to try really hard to lower the pH by any significant amount.

HTH

BTT