Low PH every few days

[campion]

A friend has got a problem with Ph levels in her fish tank.
Seems that the level drops to around 4.0 every few days.
Any suggestions as what could be causing it to go so low?

 

[juliethegr8t]

Sometimes that can be due to fish waste building up, or decomposing plant matter, things like that - makes the water become more acid. Also, her water may have a low buffering capacity (I forget what measures that, kH maybe), which doesn't hold the pH level well.

 

[Def]

Yes, it's KH that tells buffering. It sounds like she has a very low kh and something in the tank that's causing the PH to drop. I have the same problem - a KH of 2 or so out of the tap, and bogwood making the ph drop. I increase my kh using small amounts of sodium bicarbonate (baking soda), approx less than half a level teaspoon per 10litres. Adding too much will cause your ph to rise.

 

[squidlips]

by adding some dead coral or porus rock you can raise the ph and keep it level with the right amount . bicarb is good but your ph will still drop again and again .

 

[karrihug]

my kh out of the tap is 0. i keep crushed coral in my filters to keep my ph stable. otherwise it goes from 7.6 to about 5 in a day or two.