So you must be planning on keeping softies with all those nippers you got there...j/k Awesome selection of fish! I love the mystery and that tang is very cool!
For a fuge I wanted it to be seperate from the sumps. I was also thinking of designing it in a way that would allow for live rock, but prevent detritus from being trapped below, also just as in a carbon, phosphate or calcium reactor I wanted to maximize the contact time for the algaes to suck up the nitrates and phosphates in the water. Heres what I came up with.
I should add, I havent added any algae yet as I dont have any.
The water is carried into the refugium through a 3/4" pvc. I cut a plug to spray like a lawn sprinkler on the end of the 3/4" PVC. The water sprays out across the bottom of the tank and prevents a build up of detritus. Above this is the egg crate and rocks for places for pods and stars to live. I will add algae there. Finally there is an overflow back to the main sump. The flow is entirely controlled by a ball valve.