In order to determine how many heads you can use per zone, you need to know your water pressure and flow rate. At different pressures, the sprinkler head and nozzle will consume different amounts of water. For example, at 35 pounds per square inch (PSI) the 5000 Series Rotor using the 3.0 nozzle will use 3.11 gallons per minute (GPM). If your home’s water capacity was 10 GPM, you could place 3 heads per zone. Consult the Performance Charts on or inside the box your sprinkler head came in for your head’s exact performance data.