is there sucha thing called too much water flow for ur tank.. if so .. how do you know u have too much water flow.. i have 2 powerheads. ones a powersweep , 301. thinking about addin a 408 powerhead to get dead spots.
What size tank is it? Yes, there is a such thing as too much flow. Currents should be as random as possible, not like a river with unidirectional flow. If animals have to fight to stay in one place, coral is blowing off the rocks and all the sand is gathering on one side of the tank are all good indicators that there is something wrong with the flow.