refugium plumbing

[aqbio]

I am turning my 20 into a 55 with a refugium. The refugium should only have 400 GPH. Can I use an 800 GPH return pump in the final compartment if the overflow is tee'd with one pipe going to the first compartment and the other bypasing the refugium and going to the third compartment with the return pump? Just trying to maximise flow rates.
Could I instead just use a dual pipe overflow instead of teeing?
CPR aquafuge pro

[Reefmedic79]

http://reefcentral.com/gallery/data/500/526049513Reefnut_welcome.gif <br><b><i><big><big>To Reef Central</b></i></big></big>

I don't think I'm following exactly what you mean, but I would " T " your overflow pipe into the fuge and have the fuge overflow into the sump some how.