Careful though, I had my 1500's turned all the way down in my tank and the increased suction caused in the remaining hole that was open killed many of my snails that ventured too close and could not escape the suction power. Also had my small scopas get his nose caught in it. The reason I had them turned back was that they kept drifting my sand. Finally, after alot of tweaking their angle of position I was able to open them up a tiny bit without sand drifting. If you're going to have a sandbed might be better to go smaller unless you can think of a good way to disperse the flow more.