I might be misunderstanding what your saying, but the smaller the bubble the more total surface area you have. It is the surface are that captures the skimmate. If you have more air than the body of the skimmer can handle, with too much turbulance, the bubles colide with enough force to combine, therby creating larger bubbles and less surface area.
It is definately a fine line between the amount of bubbles and the amount of air, because in theory you can get more bubbles with more air.
It is definately a fine line between the amount of bubbles and the amount of air, because in theory you can get more bubbles with more air.