Sump Baffles Help

[Harris3005]

Hi everyone, I've just picked up this second hand sump for a new set up and I'm wondering how I should set it up? Should the return pump be in the section on the left withy roller filter and skimmer in the section on the right? I was thinking I'd maybe have to add an extra baffle for the return pump and ato sensor?

 

[Tomsimtim]

Sounds like a measurement question to me. I would try everything dry to see how all of your equipment fits