I run 2 250w MH and had my hammer coral about 24" below the water line (30" deep tank) and it grew from 2 heads to about 8 in a couple of months...trumpet corals, every time I try to keep them they die or just never grow no matter where I place them in the tank...For flow, I just run a big tunze wavebox on my tank so I'd say the hammer and trumpets were in moderate flow