prsnlty
New member
I have just 1 wp40 on the far end of a 6' peninsula (125g)with overflow box on the opposite end. It can be too much at times.On a higher setting it splashed out the end where the overflow is. I also have 2 returns, 1 at mid depth on the overflow end and one that runs the length of the tank below the LR Like a spraybar. To keep the water from overflowing I had to lower my surface level. I think it all depends on the setup of the tank and coral type plus other current involved for how many you will need.