Only new skimmers should have severe microbubbles. The upgrade to the MJ 1200 (as whitecloud noticed) really almost doubles bubble production, making a more effective skimmer, but increasing microbubble potential.
I've done this upgrade, and run my airflow less than midway open. Best thing is to close it, adn slowly open it up. Listen to the sound of the pump, and watch the amount of bubbles in the skimmer chamber, and keep opening the airflow until you get a nice milky chamber, without making the motor sound too stressed. Too much air will slow the motor, so you basically find a threshhold of airflow.
I think mine's open about far enough to stick my thumbnail in the air valve/knob..probably 1 to 1.5 total turns on it.
I don't have the bubble trap...and never tried to see if the pre-skimmer would fit over the maxi-jet.