Question
Hi there!...I run my water off of a well with a 13 gpm 1.5hp pump.  My current system has to be redone due to broken laterals everywhere (new leach field). I had 2 zones with 12 sprinklers total. I had 6 sprinklers coming off of 1 inch sched 40 pvc lateral lines, all with good pressure and my pump is cycling on/off every 2-3 mins keeping pressure at the tank around 50-60psi. If I add more sprinklers to this or drip irrigation off the end to a few plants on the deck, I fear I will lose pressure in the line.  I'd like to add these few more sprinklers, and I wonder if I redo the line to keep it at 1 1/4" (what it is at the filter before running down to 1" at the valves), would I keep more pressure in the line and then could  hypothetically add 2-3 more sprinklers? The sprinklers are RainBird Maxi-paws and Mini-paws. Thanks- Paul Z.

Answer
What you need to keep your eye on is the amount of water coming out of the nozzles.  Your line size at 1" should be OK, but the total usage of the system is the concern.  Find out the GPM for each sprinkler and add it up.  Since the system has a max of 13 GPM, you need to stay under that for each station.  It may be you have to install a new valve.