I really like running sponge filters on my tanks they are a great bio filter but I understand Oscars are big Bio loads. So this got me to thinking if I throw in two sponge filters rated for 55g each plus run a canister filter rated for 75g (for mechanical filtering) would that be enough for a 125G tank with two oscars? Or will I need to get a new canister filter that will do the full tank and use the sponges as a bonus?