OK, here's my situation - I have a 26 gal with 40 lbs live sand and 25 lbs live rock. I have a hang on powerfilter, and I bought a maxi jet 900 powerhead for circulation, and a visijet 100 protein skimmer. the skimmer is a powerhead with a venturi attached to an acrylic cylinder. the venturi puts tiny tiny air bubbles into the column, and a stream of these tiny tiny bubbles comes out of the bottom of the column along with the water from the skimmer. If I close the venturi, then the air isn't mixing, and therefore the skimmer is useless. If i allow the air to mix, then i am getting small bubbles in my tank water. what should i do?