this is how I pictured the sump and refugium being setup:

The sump will be sitting about 4 inches higher than the refugium. The overflow will flow into the first chamber of the sump which will contain the coralife skimmer. Then through a bubble trap to the second chamber of the sump which will have a 1" bulkhead drilled about 2" from the bottom of the sump. then it will flow through pvc to the refugium which will have another 1" bulkhead into the first chamber of the refugium which will have an overflow baffle into the main chamber of the refugium which will contain macro algae. then another overflow baffle into the third chamber of the refugium which will contain a danner magdrive 9.5 that goes to the return.

I will have a gate valve that will will go to the second chamber of the sump to limit the flow that the pump returns to the tank.

Does anyone think I am looking at any flooding problems. The overflow in my tank doesnt hold anymore than 3 gallons at any one time. In addition, could I be looking at problems from the bulkhead clogging from the sump to the refugium. That is probably my biggest concern right now, the bulkhead between the tanks clogging, but perhaps I am just being paranoid.

Any advice would be greatly appreciated! thanks!