Does pH effect tank cycling

[Mii]

I've heard that a low pH will make a tank cycle slower. Is this true? If I raised the pH temporarily to cycle it, but then let it drop back to my tap water pH since I don't really like to be dumping chemicals into my tank all the time, will the nitrifying bacteria die/stop working?

 

[fishwonder]

Yes it does for bacteria. A pH of 6.5 slows bacteria colonization by 90%. A pH of 6.0 virtually stops all bacteria from multiplying. Need to keep it around 7-7.4.

 

[Mii]

Ok so after it's done cycling is it ok to let the pH go down again? Or does it have to stay up. I might end up keeping fish that like low pH, also dumping pH raising chemicals can be kinda inconsistent. Plus then I have to pH match my quarantine tank.

 

[fishwonder]

The above stands true all the time. pH goes down, your bacteria dies. Balancing pH is not hard. Best thing to use is simple crushed coral. One tablespoon will handle 200 gallons of water forever. Will keep pH close to the 7-7.4 mark all the time. I use just 2 tablespoons in a small mesh bag and drop it in my HOB. I never have to check pH anymore. If your bacteria dies, you may have an ammonia spike now since your filter can not oxidize it anymore. Now you have to deal with that.

 

[Mii]

Then what do you do for fish that don't like high pH?

 

[fishwonder]

Most fish get used to the pH they live in and get accustomed to it. Fish in the wild move from 6.0 to 9 at times just going from sun to shade.