it is recommended that you have good current in a swf tank. it really depends on what you are planning to have. bottom line, you need good current in your tank. like i said different set ups need different current. some corals need a lot to survive some dont need as much, same with anemones, fish etc. i have read and heard it recommended a few times that you can put your powerheads on a timer to give your fish rest at night when the lights go out. i have posted this question a while back and remember this response: "the ocean never stop moving, why would you want your tank water to?", it makes sense. in my 33g set up i have a s?#@ load of current going on in a fowlr and all are doing fine. just research what you will be putting in the tank to see what is needed. IMO, i like alot.