Just wanted some input on what you guys think is the best powerhead for a 55 gal? (by the way, I have never used one before) I currently have a 55 with an XP2 and XP1, there is flow from the spray bars, but i want some movement to stir up the bottom. I have 1 small Oscar (2") and 2 small JD's. Any advice on type and placement would be appreciated. I want a simple, cheap solution to get some movement on the bottom of my tank and in some corner dead spots. Thanks in advance.