Improving Sprinkler Coverage with Low Pressure

Why 35 PSI Isn't Enough

At 35 PSI, most rotor heads won't achieve their rated radius, and pop-up sprays may not fully extend. Poor coverage usually stems from too many heads per zone, undersized pipe, or a pressure regulator set too low.

Key Questions to Diagnose the System

• What is the total irrigated area (square footage)?
• What type of plants are being watered (lawn, shrubs, beds)?
• Are there slopes or elevation changes?
• Brand and model of valves and heads?
• Is a pressure regulator or backflow device installed?

Common Fixes

1. Reduce heads per zone: Split the zone into two valves to lower demand.
2. Downsize nozzles: Install lower-GPM nozzles on rotors to match available pressure.
3. Check for a pressure regulator: If present, adjust it upward (if adjustable) or verify it's not malfunctioning.
4. Verify pipe sizing: ¾″ pipe feeding 12+ rotors is a major bottleneck; upsize to 1″ or 1¼″ where possible.

Gather the details above and you'll have a clear path to better coverage without necessarily upgrading the pump.