I just noticed that the little pump next to my sand filter has more air bubbles than usual when the pump is filtering. I've got plenty of water in the pool and my skimmer basket is clean. I've also noticed that my return jets are surging a little. I can't figure out the problem. There is one thing that's an issue, but I don't know if it's contributing to my problem...the little valve that you usually loosen to allow water to spew (after turning the pump to filter after backwashing) will not screw all the way in when it has the little o-ring on the end?? If i take the tiny o-ring off, it will screw all the way in and water won't spew when the pump is filtering...again, I don't know if this is contributing to my problem or not. Any advice would be appreciated.