Why does pH level rise so fast in aquariums?

Hey there, All fish are different and can live in different PH levels. But when the PH becomes too high it is toxic and becomes majorly acidic or basic. Some factors might be that ur using poor quality food, Not enough regular water changes, filter medium might need changing or cleaning and ammonia. Basically speaking if u have a fish that is meant to be at a PH of 7 (neutral) And ur PH is 5.7 it can really damage the fish because it is too acidic, it can damage the slimy coating on ur fish and make it open for disease and infections. Because it doesnt have that protective barrier. Same goes the other way for example 8.5 . I hope that has helped. Got any more questions? message me on www.myspace.com/wahbeagle Cheers! :oD