I have a rack set up with 2 divided Oceanic 70 gallons stacked on top of each other (essentially 5 tanks) . The tanks are drilled with 1.5 inch outlets on the back glass. What kind of flow can I expect through the bulkheads? I read the sticky for Overflows in the DIY section, but I'm thinking the flow rates would be different - (am I wrong? These are just 90° elbows surface skimming out of the tanks to length of PVC that will dump into the sump). I was planning on running with a Mag 7.5 on the return side (Think this would keep up? Top tank height is 70" at the rim from the floor)
