My fx 6 is starting to push out lots of tiny air bubbles the last couple of days. After it purges everything is good for a couple of hours but then it starts back up again. I obviously know I have a problem somewhere but what are the common areas to start. I checked hose clamps, and fitting, I am thinking the impeller is causing cavitation but I dont here any sounds from that area. Any help would be greatly appreciated especially if you had this issue.