Thank you so much for helping me out, the instructions on this thing are just absurd. Well, my tank is drilled, two holes, an intake for the sump and a return to the tank. Anyway, I have one of the holes going to my sump, which houses the skimmer, fed by gravity (this is the plan anyway). Inside the sump, the pump for the skimmer will be active, feeding the skimmer which, will return the water to the tank. Like I said, this is the plan, i guess. The problem is, with two exhaust ports on the skimmer and one hole on the tank, i must either put a Y connection on there or plug one of the holes off, its really a screwy design on red sea's behalf. One of the difficulties I forsee is with the sump. Being gravity fed and returning to the tank with a pump, how does one match the flows? I would imagine it would eventually overflow or run dry at some point. Any input or pics of your system would be very appreciated! Thanks!!