My 150 has an MP40 on reef crest at about 80 % two Koralia 8s, one Koralia 7 and the return is a throttled back T4.
My general rule is I need the following:
(Note: I said "I need" becuase if I said you need that would open the door for rebuttals, I'm not intersted in what you think I need. I am interested in what you do and think you need. I like reasons why.)
- at least two at right angles for mid height flow,
- one low for low circualting flow (optional with a vortech, maybe), and
- one high and angled slightly upward to make a rolling action out of the surface of the water all across the surface of tank water.
IMO there is no point in calcualting xx.y turnover numbers becuase the rated flows from MFRs are for single brand new pumps alone in a test chamber with some liberal math & liberal assumptions.
In a real tank many factors affect flow, such as algae on the powerhead or pump screen, two PHs pointed at one another, water hitting rocks etc.
I also think its best to ignore the return flow, it has a purpose other than tank water movement, just let that be its purpose.