Building A Refigium

[Aquascaper]

It's exactly the same as plumbing in a sump, just the tank are reversed.

 

[Dragonscales]

If you only want the refugium to ensure a place where the fish can't get to your pods, etc then perhaps an in-tank one is the way to go? Just set up a cage made from eggcrate or such at the back of your tank out of sight from the front (for aesthetic purposes) and fill it with live rock rubble.