05-04-2007, 10:36 PM
| || | Tannic acids produced by peat and driftwoods, and CO2 both can lower the pH. Depending on your hardness levels, the pH will continue to drop if the KH is not high. KH must be maintained above 4.5 dKH. Anything lower will cause dramatic pH swings which will harm your fish.
Originally Posted by FishN00b
Is the C02 the cause of the PH drop?
Are my fish doomed?
Your fish are doomed if pH swings do happen or pH lowering further. 5 is really too acidic for most fish and should be stopped from decreasing further.