Anyone ever have this problem before? Toward the middle of the day when the tank is getting saturated with O2 I notice the tiny air bubbles coming out of the outtake on my Eheim 2028 and it starts getting noisy on and off. It sounds like air is hitting the impeller, but it's tolerable. By the end of the day though the air must be building up inside and it will sometimes stop all together. Then I have to turn it off and press the priming button to get it started again. There is an external reactor in-line I'm wondering it is filling all the way up with air and causing the problem?? Anyone know how I can fix this?