So whats the GPH on your air pump, and the size (in gallons) of your reservoir? If you don't know the GPH of the pump, how many watts? You want 1 watt/gallon in general of power. I have a 22 gal. reservoir with a 650 gph 22 watt pump, and that is just about right on at 1 watt/gal to give you an idea.