I'm not much of a refugium expert, but I would do the reverse. I would have the skimmer intake in the sump, and have it dump into the refugium. That way whatever organics and nutrients the skimmer doesn't pick up goes to the refugium where it can be broken down. This is just my opinion though. Ironreef, NMreef and Johnysalt all have good refugium set ups. Guys'?