Well a closed loop system is pretty simple really. All you need is a pump and some
pvc or flexible tubing. Not sure what part of it that you need help with.
A closed loop system is basically the same plumbing as a
refugium/sump but without the tank and overflows. You just run your pump in-line with the piping so there is no dump off spot after it leaves the tank. It just runs right into your pump then the return line goes right back to the tank. The return side can be as elaborate as you wish. You can add a SCWD device to create motion. You can have it just come out of a bulkhead. You could add a spray bar to distribute the flow where you want...the options are pretty limitless on how you get the water to the tank.
ryan 
Linear Mode
