For most of my years in salt water I used only power heads, recently I decided to purchase a couple of timers from a local hardware store and plug my powerhead into the timers to make my own sruge monitors. I do think that the corals do like the wave action better when there is heavy movement then lower movement. I set one timer for on three hours and off for one hour set the other for on two hours and off for one hour, i have one power head that runs all the time in the tank. The sun coral is out more during the day and the soft corals have jst taken off in growth. Some of my SPC look like they are growing a bit faster, but hard to tell as they do grow more slowly.