Poorly designed irrigation system. Need help.

Discussion in 'Irrigation' started by CRUZMISL, Jul 22, 2004.


    CRUZMISL LawnSite Member
    from zone 6
    Messages: 186

    Hi All,
    Great forum! I'm not in the buisiness but LOOOVE a green grass which brings me to my question.

    I had a sprinkler system installed about 4 years ago. My lot measures 100x200'. I have 9 zones with 4 rotors on each zone. All of my equipment is Nelson with 6000 heads. I have ALWAYS had problems with dry areas. I kept calling the company out and they kept adjusting which just moved the dry spots around. Frustrated by their incompetence I found Jess Stryker's website. Very informative but WAAY over my head.

    My static pressure is about 52psi. When the system is on it drops to about 40. The water supply according to Stryker's formulas is only good for 10gpm. Since I have 4 rotors on each zone I am currently maxed since the nozzles are rated at 2.5 gpm each.

    The sad thing is this is the busiest irrigation company in town and they have NO idea what they're doing. All my nozzles are the same, including the ones that are 1/4 circle, 1/2 circle and full circles. This is clearly over/underwatering areas (funny I still have dry spots in the over watered areas). I wanted to change the nozzles but Jess suggested not having nozzles flow less than 2.5gpm due to wind. 2.5gpm per head is the max my system will run.

    I am so confused I don't even know where to start to try and fix this problem. Any suggestions?

    Thanks !!!

  2. DGI

    DGI LawnSite Member
    from SE Mich
    Messages: 173

    My first question is this: Do you generally have head-to-head coverage?
  3. JimLewis

    JimLewis LawnSite Fanatic
    Messages: 6,876

    The MP Rotator would likely be an excellent choice to fix this problem. Educate yourself on that product. It's ideal the situation you're describing.

    • Designed specifically for low-flow/low pressure situations
    • designed to be wind resistant
    • simple to change over from your existing heads

    You'd have to change over to pop-up heads and remove the rotors. But that's very simple.

    And you'd have to water longer.

    But I bet these would solve your problems.

    CRUZMISL LawnSite Member
    from zone 6
    Messages: 186

    I would say yes I do have head to head coverage BUT the streams from one sprinkler head only overlap th other by about 2-3 feet or so, if I recall. It could be more but I do know the streams do not come close to touching the neighboring head as Jess suggests they should.

    The MP Rotator looks interesting. Anyone ever used them?

  5. Mdirrigation

    Mdirrigation LawnSite Gold Member
    Messages: 3,793

    Sounds like a precip rate problem, all the nozzles should not be the same , a 90 degree head should have a smaller nozzel than a head doing 180 or 360 degrees. You say they are the busiest , they are probably the cheapest also , its the same way here , the busiest companies dont take the time to do it right , they are busy because they under bid. Call another contractor with expereience . Wind should not be a problem , since you water in the early am , there is generally no wind.
  6. JimLewis

    JimLewis LawnSite Fanatic
    Messages: 6,876

    Yes, we use them all the time. We're installing a system next week with 45 psi and have designed the system to be used with the 30' MP Rotators.

    We also use them to fix poorly designed systems where there isn't enough pressure or flow for current heads. So then we retrofit the system with the MP Rotators.

    I even installed them in my own yard just because I love the way they look and because they have the best matched precip. rate available.

    Haven't had one go bad yet. And we've been installing them for a year and a half now.
  7. earthtool

    earthtool LawnSite Member
    Messages: 115

    We also retro fit with the MP 2000 and 3000 in low flow systems.
    At 40psi the 3000 will give you 360 degree coverage 30 feet, 3.64 gpm, 0.39 in/hr. to 0.48 in/hr.
    Great way to get good coverage without allot of dough.
  8. MOlawnman

    MOlawnman LawnSite Member
    Messages: 161

    Just started using the MPRotater myself. And so far I think they're great. I also just recently discovered that RainBird has come out with the same kind of nozzle. I'm interested to see how well they work.

    CRUZMISL LawnSite Member
    from zone 6
    Messages: 186

    This is awesome. The MP's really sound like the way to go AND they look awesome running. How would I install them in place of the Nelson 6000's I have? It appears they just screw right into the existing housings. IS there a guide I can use so I order the right ones? Lastly, where can I buy them online?

    Thanks a ton!! The possibility of resolving this is really making my summer.


    CRUZMISL LawnSite Member
    from zone 6
    Messages: 186

    Also, how much are they?


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