Lights in sump?

[fishface]

if there's nothing that's photosynthetic then you don't really need a light. live rock for instance doesn't need light, macro does. refugium and sump are sometimes terms that are used interchangably...sump's are mostly just a place to exchange water, keep skimmers, probes, auto top off's etc. refugiums have macro, live rock, critters, low light corals...whatever you want. it's a place where no peretitors can eat copepods, hence the name reufug-ium.