Powerhead Placement

But you said its blowing sand and stuff around correct? so go smaller.

 

I was not able to use my hydor Koralia nano powerhead in my 10 gallon either. The way I had aquascaped and the corals I put in there, it was just too much movement. Plus the first fish I added, a very small yellow candy hogfish, stayed on one side of the tank behind some rock. When he did try to swim out more you could see him getting blown sideways. I had the powerhead towards the top, on the side and pointed somewhat up (the nanos are not that adjustable). With that powerhead and my filter, the flow was about 365 gph. As soon as I turned it off my fish was swimming all over the tank and my pulsing xenias, which had stopped pulsing, were back at it again. So I think alot depends on how your rocks are arranged, the corals you want to keep, how much sand you have, etc. to determine if the water movement will be too much. I'm considering just putting a bigger filter on my tank to up my movement. I probably will only add one more slow moving, docile fish to that tank and low-flow soft corals.