Bottom diffusers are used to move water to the surface (and back to the bottom), not to add O2 to the water. Think of bottom diffusers as water pumps. Surface aerators are O2 injectors.
The waterfall is a great O2 injector. It is one of mother natures bests O2 injectors!!
Unfortunately a surface aerator isn't really an option cause of the amount of electricity they use will a bottom diffuser be enough to keep sufficient oxygen levels in my pond?
