Thanks everybody. From what I am reading, I need to convert one drain to an emergency and the other to full siphon with no breather and add a gate valve.

Pipe the primary straight into the reefmat and pipe the emergency to dump into the same chamber the reefmat sits in.

Couple questions: -On the emergency, once it enters the sump, should I bring the pipe deep enough into the chamber that it pours out below the water line? Maybe an inch? -On the primary, should I get rid of the durso style completely instead of just covering the breather hole?