We put in a new sand point well 28 ft down 11ft of water in pipe.Pump is 1/2 horsepower and 42 gal. bladder tank.We get air in water every time pump turns on ,if I run water and release air I will get no more air until pump turns on again. We were gone a week and when I ran water until pump turned on at 30psi the water looked like soap bubbles and I had to prime the pump. I then ran water for a hour and it pumped fine ,once I used water again same problem a spurt of air and then water runs fine. Whats the problem?