I was curious on protein skimmer operation. Whenever I open the valve (even slightly) I still get micro-bubbles coming through into the tank. (I have a Red Sea Max I set up for my daughter). If I turn it down enough to where I don't see bubbles, I can't really tell if the skimmer is doing anything, as nothing is removed. Do these micro-bubbles harm anything in the tank? Or, do they actually add any oxygenation? I'm not sure what else I could do if this is a problem.