So my 48x24x24 has 4 MP40, all 4 at 2 end of the tank. 2 at front end, and 2 at back end. My aquascape is kind of like 3 island type, so my question is this. Should I run at 100%, or reduce it to 75% or below. 75% already started to knock my sand around in to their own little hills, so I'm thinking of removing them this week since it's only about 2-3 inch sand bed during water change. Also 2 & 2 is sync, should I unsync it?