So I bought a powerhead/wavemaker that moves 790 GPH for my 60 gallon tank. It says that it is recommended for 50 gal and up. When I put it in I face it towards middle center. After doing this I can definitely see there is a flow in the tank which I like but it looks like my fish are fighting for dear life to not be swept away. Do I need a less powerful powerhead or am I doing something wrong?