Irrigation Installer Wants to Reduce Nozzle GPM: Is That Right?

Evaluating a Contractor's Plan to Lower Nozzle Flow Rates

A new 11-zone system shows 30–35 PSI on the pressure tank gauge (lower when household water runs). Installers plan to "reduce heads to lower GPM." Homeowner fears reduced coverage and longer run times.

What Lower GPM Nozzles Do

Reducing nozzle GPM decreases flow per head, which can help if the pump/well can't supply enough total GPM. However, it also reduces throw distance and coverage unless you swap to heads designed for lower pressure/flow (e.g., pressure-regulated or low-angle nozzles).

Better Alternative: Split Zones

If coverage suffers, ask the installer to "split the system" by adding valves—move some heads from overloaded zones to new zones. This maintains proper nozzle sizing and pressure per zone.

Red Flags

• Sales pitch promised "plenty of pressure."
• Heads already cover each other (head-to-head spacing).
• No discussion of pump/well capacity vs. design GPM.

Insist on a written performance guarantee before accepting nozzle changes.