I have a 50 foot well using a new submersible pump that has worked well for 6 months, now when you turn the water on is cuts on and off ever few seconds. Does not run unless the water is on somewhere. We have about a 30 gallon tank that has no bladder and no valve to put in air. There was NO guage put on the tank when it was installed. I by passed the pressure switch and there was plenty of pressure, Tank was full. HElP!!!!!!!!!!!!!