I'm not sure if what I'm seeing are micro bubbles or not. The tank looks cloudy all the time, you can see fine particles moving in the currents. When I look at the water in the filter area, all chambers have crystal clear water. The pumps are submerged with at least 1" of water above the pump. When i turn the pumps off and let it sit a few minutes you can see everything hanging suspended in the water. In the filter basket I've got the sponge that came with it, some cheato in the middle section and the bio media in the bottom. I also left the two long pieces of sponge that line the side of the pump chamber where the water overflows into it. \n\nAny ideas?