I'm thinking of converting my UGF to RUGF, by reversing the flow of my 802 powerheads. (See the thread I started in General Freshwater.) I want to prefilter with a black sponge; where can I get one? The LFS has white, yellow and blue filter sponges, but not black. Could I use the type of sponge they use for "stipple" painting?
I prefer the Tetra PHAS sponges. They are a bit denser foam than Marineland's and they trap debris better. Go to Drs. Foster and Smith (http://www.drsfostersmith.com/) and do a search for 'PHAS'. They're cheap -- only about $4.