No, I seldomly need to make any adjustments. You might have to wait for the skimmer to break-in though before you get any consistency. Are you using a multi-valve like this to control the air?
http://www.hagen.com/canada/english/...01011580010101
The Optima even at its lowest setting is too powerful. So, you can have 1 valve going to the skimmer and have 1 valve to relieve the backpressure of the pump.