i'm setting up a 135g and was planning on using a couple sponge filters in the corners. i was going to use a AC 70 powerhead but was wondering if anyone has tried pushing water through the sponges. i was thinking that by using a prefilter to clean the water and hooking up the venturi you would push oxygen rich water into the sponges and maybe increasing the bb effectiveness. any thoughts or reasons this wouldn't work? also wondering if this would provide pretty good bio filtration (won't be the only filter but have heard these things can run large tanks by themselves)