Ok. So I just bought a Mag 18 for a steal of a deal, used of course. I don't even know if my tank can take that much flow. I'm in the process of building my first non-nano tank. I have two drilled returns and a lower spray bar. Will this be over board? Will there be to much heat from this sucker? I also have a overflow with a a 1.5" and 1" drain. So that should pour a lot of water to my sump for the Mag to take care of. Total impulse buy.