You can also try to bounce the flow off the rocks too, diffuse the flow and you will get good circulation around the rocks.
Thats the whole idea of powerheads, to keep sediment from forming on the sand and getting it floating so that your filtration can catch it. Also really good for gas exchange and can help keep your ph stable.
180g Reef - 60g Rimless Reef -90G FOWLR- 125g Malawi Cichlids- 40b REEF- 34g Fresh Planted-working on- 20L FOWLR- working on
I have a mix of many different saltwater fish amongst my tanks, but I love my Tangs most of all.