No, that has to do on *where* your returning the water back to the sump. You'll need to find a way to eliminate them in the sump. Typically you would use the dripplate (with floss if needed) to help get rid of them also you can raise the level of water on the skimmer's return side. Being that deeper water will help dissipate the fine bubbles. Dont fall into the trap of just one large foam block, although it will help, it will take away from the free flow system I try to encourage. See pg 157 & 55 -56 for correct placement / control of skimmer water Robert