I have a 75 gallon with an corner overflow. I am getting a new return pump either way because it sometimes requires a tap on the side of the sump to get started. I don't trust it to restart if the power flashes. Right now I have a mag 7. What is a good quiet pump to get? I have a fowler. I am also seeing Microbubbles (nothing too bad). I have a Reef creations MR2 skimmer, but I don't see many bubbles in the return chamber after the bubble barrier. It is an oceanic reef sump. Can the return pump if it is worn out be making the bubbles? Is this unavoidable? Should I put a piece of filter over the intake to the pump?