as the title says I'm looking to get a hang on the back refugium, its for my 20g tank, I just don't see the point in putting a 20g long sump on a 20g long tank just to get a refugium and stuff out of it, although I will undoubtably end up taking that route eventually. So anyway looking for a hang on the back refugium doesn't need to be huge as it is I have little enough room on the back but i suppose I could always put the filter on the side or something 