wtb

[TheReefGeek]

What kind of overflow are you running?

What aren't you happy with, the total flow in your tank? I wouldn't push more than 6-700 gph through a single 1.5" bulkhead, although if you use a durso you should be able to push it and use a mag 12.

If you have 2 x 1/2" returns, I would go max 450gph out of each, so 900gph total. So with head pressure, the mag 12 should do that job. If you get a mag 18, you will probably have to throttle it back so it doesn't overdue your overflow. You can t-off your return line back into your sump with a valve, or just use a valve.