Go slow flow and make your whole sump a large fuge. Use powerheads for flow. I am in the process of redoing my hastily setup 200 to make it more like my old 75g. It was as stable as it gets. MY 48 had 2x2" drains and it was ran by a mag5 split in two. There was nothing in the sump, the display was just macro rock and sand. It used to house seahorses, but they always managed to wiggle through the egg crate and die. Very rarely did I clean the glass!