Originally Posted by Kumo
Massive water changes (50-60% most) should only be done once a month. Once a week water changes should only be done with 20-25% water changes.
I buy prime, quick start, stress zyme and stress coat to help keep my ammonia and nitrite levels at zero, or close to zero.
Massive water changes can possibly send a fish into shock, so that's why "massive" changes should only be 50-60%.
Why should the water changes be as such, as opposed to the countless other ways to do them?
You should not need to add quick start or stress zyme to keep your ammonia and nitrite levels at 0. That's what the bacteria colonies do.
As I said, the only way there would be shock is if the parameters, particularly pH, were very different, which can happen if water changes are never done. Assuming a regular water change schedule, massive water changes are absolutely harmless. In my experience "regular" is at least once every 4-6 weeks.