Hi, I have a problem which just started recently. It seems everytime I turn a faucet on almost anywhere in the house the water starts to flow then suddenly spits air for a few seconds and then returns to normal . I have checked the pressure in the tank as I am on a well system and the pressure is holding fine. the pump kicks on at 30lbs and off at 60lbs, the pressure in the tank when drained is at 29lbs. Any idea what could be causing this???