Slowing down the off time and allowing it to completely fill actually screws up the timing of the waves. They seemed to cancel eachother out. I found after playing with the timing that I got the best waves when I used the same amount of time for the on and off cycles.
I can draw something up. I'm going to rebuild this one though. After watching it, I realized that I think I can make it around 4"x5"x12" and have it work just as well.
Pat "PHReef" sent me a link to this one http://www.exoticfish.com/details.cfm?cat=0|1978|1963|1908|0&id=42463&
anybody try one of these wave makers yet.