That powerhead shouldnt be producing bubbles on its own. Its either too close to the top of the water, try lowering it a little, or you're sucking up air bubbles from somewhere else and its chopping them up into smaller finer bubbles. Or...you dont have the air hose and venturi hooked up to it do you? That would obviously be adding bubbles too. But, like i said...it shouldnt be producing air bubbles on its own, there is an under lying cause. Figure out what that is, and it should work fine for you!