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New Member


Monday, July 16th 2018, 10:16pm

Major system design FAIL


I've had bad luck with irrigation system design and installation and it's time to start fixing. This is actually my second experience correcting the work of others. I hope to chronicle my approach here and look to this forum for help. I am by no means an expert, just a lawn enthusiast who has done a lot of reading about irrigation.

In my previous home, I had a system installed that required some pretty significant re-work . It was a 1/4 acre property with a well, and all of the zones were installed with Hunter PGPs with red nozzle #6, regardless of rotor arc. My well would cycle on and off during operation, so I re-nozzled each zone with a matched precipitation nozzle set that achieved a constant pressure at the well pump during operation. I also had to move a couple of heads to improve the head-to-head coverage.

I purchased my current home a couple of years back with irrigation system already installed. Some specs on the property and system:
  • 1 acre property (recently acquired an additional 5000 sq ft adjacent property)
  • well service
  • 40-60 psi pressure switch settings on well pump
  • 3/4 hr Goulds pump - not sure of gpm of well, pump likely puts out about 12-15 gpm, never had an issue with drawdown or recovery when running water for hours at a time
  • 9 rotor zones, all Hunter PGP
  • Each zone is 4 or 5 rotors, all #6 red nozzle
  • Hunter jar top valves
  • Hunter Pro-C controller (2008 era)
  • Hunter Mini-Clik wired rain sensor
  • Slight to moderate slope on the property (lowest back head is about 10' down from the master valve; highest front head is greater than 10' higher than the master valve)
  • Mostly open, sunny property, some shade around the house and along southern wooded side

Some things I know are definitely wrong with the system:
  • Irrigation was installed to only cover about 50% of the 1 acre property, needs expansion to cover the other 50% (deep backyard) and the newly acquired 5000 sq ft.
  • Well outlet is 1" and reduces down to 1/2" copper before expanding back to 1" poly at the master valve
  • No PVB on the system, only a single check valve at the well pump outlet
  • Head-to-head coverage not achieved in many places
  • Hunter PGPs failing at a rate of 2-3 per year, rotation issues and puddling around the heads
  • Rotors are not set up with matched precipitation nozzles, well pump cycles (relatively small pressure tank)

Some things I've already done:
  • Fully mapped system
  • Matched precipitation by re-nozzling, using all Hunter blue nozzles
  • Re-nozzled all zones using matched precipitation nozzle sets that resulted in constant pressure at well pump (approximately 50-54 psi) when in operation, eliminated pump cycling
  • Replaced some of the failed PGPs with new PGPs
  • Replaced two leaking Hunter valves at start of last season
  • Replaced Hunter Pro-C controller with Hydro-rain 16-zone B-hyve (I got tired of walking back inside to turn things on and off when adjusting)

Some things I plan to do in the near future:
  • Replace wired Hunter rain sensor as it is not working properly with the new Hydro-rain controller, planning on a Hunter wireless sensor (had one at my old house that worked well for the 6 years we were there) as soon as I can confirm it works properly with the B-hyve controller
  • Move some of the rotors to achieve better head-to-head coverage in the area where irrigation exists currently


New Member


Monday, July 16th 2018, 10:40pm

Some of my questions, to start:
  • Is it practical to consider irrigating about 1.25 total acres with a drinking water well as I've described it? I'm currently running it about 2.5 - 3 hours per night, 6 days a week (zones are broken up in to two programs which alternate days) for the fraction of that which is covered, and I'm still left with what I'd consider a semi-dry lawn during the hottest parts of the summer. I'm concerned that if I expand the system, I will need to run it 4-6 hours a night or more, which I can't imagine is good for a well pump long-term.
  • Should I be looking to upsize my supply line from 1/2" to something bigger (1", or 3/4" at least)? I don't know how restrictive the 1" is for my system. I get good distance out of the rotors, but flow is not overwhelming. I've often wondered if the 1/2" supply could be a factor.
  • How would one design a proper PVB installation with such a grade where the highest rotor is at least 10' above the water outlet location? I know the check valve is not right, but I've not known the best way to address it considering the grade on my property.

I'll try to post some pictures of my changes as I progress.

Thanks in advance to all who jump in to offer assistance.

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