I've got a powerhead 3c1 in our tank as well as an ehiem external filter which creates an excellent current and also two 4 inch air stones. Do you think I need the powerhead as well? The fish seen to like playing in the current occasionally but most of the time they don't go to that end of the tank. I've got it in the right back corner facing diagonally. If I was to reposition it would that be better or shall I chuck it out !?!