My home's water supply is spring fed. We have a holding tank approx. 500' to 600' fromthe house and about 50' to 80' lower in elevation than the house. We have a submersible pump in the tank (with a backflow preventor thanks to an earlier TOH tip) and then the nomral setup at the house. Backflow preventor, pressure switch, pressure tank, water filter. The problem we have is that when using a large amount of water, the pump will cycle 3 times and then go to zero pressure. We wait and in about aminute the pressure comes up again. The water level is fine in the holding tank. I cleaned the pressure switch yesterday and afterwards it worked fine, however after filling two horse water troughs, I am back to square one. I know putting a filter before the pressure switch can casue problems, but is there any other way to stop the sediment from interfearing with the pressure switch operation? thanks