The bubbles don't bother me so much. I tried tracking them down, replaced the 3 way sandy valve rings, replaced the clear top, the top o-ring and it still bubbles. It doesn't bother me.

The noise, however, is bothering my neighbors so I want to fix that issue. My gut is telling me bearings, but i never thought of the impeller. I guess I could disconnect/remove the impeller and just run the motor with it not connected and see if it's just the motor making the noise?