48x20x15 sump tank / help needed

[corrosionjerry]

Ok... I am in the process of putting together my sump from a breeding tank I had for FW..

Just wondering how I should section this thing off / I want to use part of it for a refugium... any thoughts on what size I should make each section...

The Mother tank above is 48/18/20... I plan on using a 800G return pump with a couple of 1200GPH PH... the tank has an internal overflow box with 1 1/2 outflow and 1 inch return...

I plan on using an in sump protein skimmer