I think the ecotec site is a bit skewed. I also noticed that it doesn't consider a return pump of how grown in the reef is. Yea, no return and huge spa the site is probable correct. If you have a young reef with a strong return you don't need nearly what they want you to have. I have 1 mp40 on my 120 with a mag 18 return. My corals are getting big so I do need some more flow but the one has served me well for about a year.