I have posted a few times at cpraquatics.com. They have some ownership or collaboration w/ the manufacturers of the aqua-lifter pump AFAIK. That's why they "push it" so hard. I read many threads on lots of different forums before I bought the CPR overflow and most of the time if there was a problem there was a common factor-the aqualifter pump. It's just not powerful enough. The people who use Rio 600
(?) or MJ 1200 had good results(I would avoid the Rio for other reasons though). Another good thing is you can hide the ph in the sump and just run an airline up to the overflow. FWIW I can run my Mag 9.5(950 gph
) wide open w/ the CS90(600 gph
). The only problem is the flow is too much for my sump and bubble traps. Micro-bubbles end up getting back to the display tank. IMO
the MJ 1200 w/ the intake venturi fits the CPR overflows PERFECTLY! I have just a few small bubbles in the "C" of the overflow at any given time. Keep in mind that any bends or curves in the overflow tube/plumbing will cause restriction. Good luck.