I want to install a sump and refuge in separate tanks

[Proteus]

There are other ways to go. You don't really need a DSB. Prodibio, zeo, gfo,Biopellets, vsv are all great ways to lower nutrients in tank especially with room constriction

I have a nano tank with a nanoer sump. Sump has filter sock rubble skimmer reactor and return pump. I dose prodibio and have sps dominant tank. For my years of service only being two years I'm very happy with my results