This will be my tank to upgrade my oscars into. I have them in a 30gal. Cause they are still small. But a guy from a lfs to put a air filter in. They gave me a sponge they alrdy had bacteria on. So i tried that and everything has been ok.
The easiest and quickest method i have found is to use some filter media and substrate from already cycled tanks. And then fill the new tank about half full with water from cycled tanks, finish filling with fresh water treated with prime.
