We are going through a terrible drought. I have a 3 acre pond I want to use to irrigate my lawn. I hooked up a 1 1/2 HP pump with a 1 1/2 inlets and outlets. I hooked 3/4 pvc to the outlet of the pump and the the flow starts out good, but then goes to nothing. Do I need to run the 1 1/2 size pvc to the springler heads rather than going from 1 1/2 at the pump yo 3/4?