I had 4 of them on my old 330G tank ( got them from KTH sales ) ... had them on 2 closed loops with mag 18's ... I now have a temp 270G setup with 1 on a mak 4 return and because the mak 4 is pressure rated it produces more flow than the mag 18's. Well worth the investment IMO especially for large tanks as you can produce 4 to 5 times the flow from a single pressure rated pump and cut down your eletricity costs
