I have been pondering this for a few days now. I am going to set up a 20g Standard and I have 1 Aquaclear filter that I got used. I was just going to run it as a fuge. But I saw a set up with 2 Aqua Clear filters 1 was a Fuge and the other was using the filter media that came with it. What should I do??? and what size should the Aqua Clear Filters be? I think the one I have is a 50.