Michael_G said:whew!! i can afford a tank then.for a 55g would a ac 300 be ok they say so on their site. the skimmers at big als is 16$. not as bad as 150$
You can never overfilter. I have an AC300 and a Fluval 404 running in my 55g (1-oscar, 1-pleco). Also, I figure if either ever breaks down, one or the other can handle the bio-load by itself for as long as necessary. For smaller fish, I'd watch out that you are creating too much current for their happiness though. Maybe multiple smaller filters are better than 1 or 2 huge filters in the case of small fish. With only an AC300, my 55g would have a lot of dead zone though.