i thought about that too, i just know that live rock is supposed to be the best filtration(?) and i know a skimmer is is a given but I'm just torn, not just about the overflow but also live rock, i read to keep it not in the display but yet not in the sump, so where is truly the ideal place for that rock? In the tank with a closed loop and high flow over said rocks, or in a sump with a high turnover rate over the rock, or.......?