I know this should be really common sense, but I'm not 100% sure that I get this...Currently, I have a 90 gallon tank that has a standard overflow that drains into my sump, then using a return pump at the other end of the sump, water is returned back into the main tank. I was looking to setup up another smaller tank next to my display tank, and run it as a refugium. For whatever reason, (maybe I am making things more complicated then they need to be) I don't quite understand how this would be plumbed. Do I need to take all the overflow water into the fuge, then go into the sump, then back into the tank? I have read lots of descriptions about this and usually they tee off from the main drain line, to regulate flow. Like I said, I'm just a bit confused about this, and if anyone can shed some light on this, I'd sure appreciate it! Thanks, Rocky.