why couldn't you build little closed loop systems into your overflows? I'm thinking you could easily drill a couple of holes in each overflow, then drop a power head and SCWD inside? No glass to drill and possibly comprimise. Of course i realise it would be a little tricky to acualy do this work down inside the overflow, but i think there would be enough space for everything. Righ now i just have hagen 802's inside my OF's attached to a short length of flexible tubing and then an output for a magnum canister filter which has a nice little deflecter on it that spreads out the flow well. This works well, but i was just thinking it could be improved on.