If your home's water flow rate is 10 gallons per minute, you should be able to place at least three heads per zone. The number of sprinkler heads you can install depends on a few variables:   ● Water pressure  ● Your backflow device  ● Zone valves  ● Sprinkler head brand you purchase  ● Improperly sealed pipes ● Other factors   Be sure to check the performance chart or design manual that comes with your sprinkler system.