Probably, if you do regular water changes like your supposed to, and you don't over feed your fish. If it turns out to be just shy of needs, you could always offset it with a decent HOB. I use a canister rated for 175 on my 150, and I still use 2 Aquaclear 110's with it. Granted I don't know if its enough for 1 Oscar yet, as it still undergoing new tank cycle.