I have a 1600 gal/hr intex pump for my above ground pool. I recently just installed an outside wall skimmer and I'm having trouble getting rid of air bubbles in the pool pump inlet. Have removed everything and tightened everything and still having air bubbles. I have a shut off valve below my skimmer and I notice the O ring in between that is a little smushed. Can that be causing air to be sucked in to the pump?