Keep the pump at full power, use the controller to tune the frequency. Start with the knob turned all the way counterclockwise and in hair width increments turn it clockwise waiting a few seconds between every adjustment to see if a wave develops. Each tank has one frequency which will create a wave, in any other setting nothing will happen or just a little splashing and random chaos. When you get the wave correct it will crest on one side and have the trough on the other and you can fine tune this to get the maximum height with very, very small adjustments. Once you have the wave perfectly tuned you can use the pump power setting to reduce the height of the wave if you need to.