I need help with a water well problem.?

America is right it is all a matter of gallons per minute. (gpm). My math show that your pump is filling the tank at about 5.6 gpm. I dont know how many sprinklers you are running at on time but a full circle pop up sprinkler is going to put out or use 3.5-4 gpm a 1/2 circle = 1.65 gpm a1/4 circle= .92 gpm. A typical system using 3/4 inch pipe can use only about 8gal of flow /min. I suspect your pump just cant keep up with the demand. I would suggest you first need to determine what your pumps capacity is supposed to be. If you dont know ask a well contractor. According to a brochure by Toro irrigation any pump used for irrigation should be able to produce 45 psi (pressure) at 10 gpm. You can change the lay out of your sprinkle system by adding in more valves thereby reducing flow or you might change to heads which put out little fingers or streamlets of water. These nozzles educe the flow but have to be run twice as long. Check Toro Irriagation, Rainbird , Hunter Sprinklers or Orbit for more info on sprinkler design and water use. Note the pressure difference between recommended and your pressure capacity.