do you want the surface of the water always breaking? i can adjust my powerheads downwards so there isnt much movement along the actual surface, as if all the water is being pushed down. in my big tank however i have two powerheads and then four return pipes. the left side have the return pipes have one going behind the rock and the other towards the wall to send water behind the powerheads... on the other side i have one facing downwards behind the rocks and the other at the surface of the water.. its certainly causing the water to move more along the surface, actually looks better to me than before (And we definitely have good movement overall in the tank) i was just wondering what would be considered ideal?