[musho3210]

Hmm, that tank is a bit small for an oscar, they are big waste producers so you will need the best of the best filter. I would suggest a wet/dry sump (if you dont know what it is ask someone cause i cant be bothered explaining). Or you could use a canister filter. A Bio-wheel is a compact wet dry bio medium where beneficial bacteria should live in. You could get a bio wheel filter but not by itself.