I've got a 150gal setup with a 100gal (more like 60 gal actually used) stock tank as a sump and about another 70gals of smaller tanks also tied into the system. I do have room in my sump to throw some macro in there, but my sump isn't really compartmentalized and is mostly full of live rock. I figured that by going with some sort of reactor/scrubber would be more effective giving me better a chance of actually tackling the hair and slime algae issues that I have.