Overflow box size??
 

How big does the overflow have to be for my 54gal?I have a Aqua Tech 30-60 hob filter,is it of any use to me as an overflow(maybe just the filter box).
Any help I can get in planning this would be greatly appreciated :biggrin:
The tank is not drilled(already set up)so I'll be using return lines with elbows.I really have no idea when it comes to plumbing and set up of a sump.

Jim

O/F size
 

Try this calculator:
http://www.reefcentral.com/calc/drain.php