How to arrange this sump for a refugium?

[somekindabonita]

We have this homemade sump that came with the setup we purchased used. The previous owner said this was the configuration they set it up, but we'd like to add a refugium in if we can figure out a good arrangement!

It's not possible to take the sump out without draining the display tank, so I can't reasonably replace it with a new one. My husband thinks it would be challenging to try and move the baffles around/silicone new ones in while the tank is in the stand, so that's not an option either.

My thought was using some egg crate wrapped with thin screen to block off a small area in the last section for the return pump and ATO, so that we can use the rest of the area for chaeto. This is the light I plan to use: https://www.bulkreefsupply.com/mini-led-refugium-light-finnex.html

Is that a terrible idea? Are there any other suggestions?

 

[Peach02]

if your looking for a large refugium you'll need to plumb an external one but you could defiantly get some cheato in that middle section or as you said sectioning off the return section

 

[Gonzo74]

I think you could section of the return section. Would not be that difficult.