PH crash (symptoms and how to avoid)

[ButtNekkid]

Hi all,

Just wondering:

Is there such a thing? At what ph does it occur?
What symptoms do fishes show when it happens?

I know that KH plays a big part at buffering but what else helps keeping ph from crashing?
How low KH still keeps ph crash at bay?

I have a 15 gallon that has about 1/4 of the substrate with peat and I do all my water changes with peat treated water.
My tap is about 1 dGH and 4 dKH (120 µS). I find that my livestock are more colourful and "livelier" when doing WC with peat water.

 

[Bart Hazes]

A low pH is not a pH crash. Using a peat substrate and peat treated water are aimed at achieving a low but stable pH, presumably to keep fish that are adapted to such an environment. A pH crash is when the pH suddenly and unintentionally drops due to the release of acid in poorly buffered tank water. Fish not adapted to low pH get in trouble because some proteins stop functioning properly. I read a study looking at salt uptake in the gills for fish adapted to very soft acidic water. They could do it but apparently the proteins that take up salt in other fish are compromised at low pH. I have not seen a pH crash in my tanks so can't tell you what the symptoms are but as long as you keep fish that ccom from acidic waters your peat treatment should be ok or beneficial.

 

[gerald]

Fish species that are not adapted to low pH may show rapid breathing, cloudy fin edges, hazy eyes, and their behavior may become either more frantic (trying to get away from unsuitable conditions) or listless (weakened by osmotic stress). My tap water has high pH but very low KH, so pH in a tank with a heavy fish load (lots of acidic nitrification happening) can drop pretty fast (from 6-7ish) down to 4-ish once the little bit of KH is used up. pH drop happens much slower in tanks with a light fish load (Apisto tanks) and plenty of plants. Aragonite/ crushed coral is my usual solution; very small amounts for soft-water tanks.