I have been having an issue for approx. 3 years now...the set of jets that run off the main pool pump and switches to the spa control is not pumping any air bubbles into the spa. This hasnt always been an issue, during the first few years I had the pool there were bubbles visible. I also have a second pump that controls aux jets in the spa and it functions fine with air bubbles. Their are two pipes next to the equipment with holes drilled in the caps. When functioning correctly there is suction from the tube and then I get bubbles. There is currently no suction from that particular pipe for the main pump. The pump does work and there is water being moved just no air being introduced. Anybody have any ideas??