Reef with a few fish. well, my sump has a refugium, as well. And, when I move everything from my 55, the 55 gall is going to be a giant refugium. So, my total watter volume will be 120 +55 +(about) 25 (sump)=200 gal
. But, are the bioballs in the overflow box, and the first sump chamber just a waste of time?
sump is about 50% refugium, 30% bioballs, in their own chambers, of course.