i run a closed loop on my tank. i used a mag 7 as pump and a 3/4 scwd for about 2 yrs and never had a problem but feel power heads produce better movement. may be better with a mag 12 but i am to lazy to change out pumps… lOl
I think I am going to silicone over all my holes in my tank and ditch the CL idea. Just go with about 4 K4 powerheads. Cheaper, more efficient and easier to work with, just looks bad.