Poorly Planned Zones
Another thing that may contribute to poor water
pressure is a poorly planned zone. If there are too
many sprinklers on one zone your pump simply can't
supply enough water to meet demand.
If you have a zone that has more sprinklers than the
other zones and is performing poorly, this is probably
the case. To fix this problem you either have to
eliminate a sprinkler or move one to a zone that does
not have as many.