WM Smartline/prec. question

Discussion in 'Irrigation' started by Remote Pigtails, Apr 22, 2007.

  1. Remote Pigtails

    Remote Pigtails LawnSite Senior Member
    Posts: 581

    Trying to determine if I like MP rotators I switched out a zone on my system from 20' brass spray to rotators. I reconfigured my WM smartline on that zone from spray (default is 1" ph) to a .5" ph setting. We can only water 2 times a week here so I like to see how many minutes have accumulated before its next watering time. They spray zones all show 10 min and 16 sec. The rotator zone shows 30 min and 50 sec. Did I miss out or have forgotten some math from my early irrigation training? It seems to me the MP zone should be at 20 min and 32 sec. All other factors are the same. Warm season turf, clay soil, 10% slope.
     
  2. PurpHaze

    PurpHaze LawnSite Fanatic
    Posts: 5,496

    You'll have to compare the GPM and precipitation rates of the MPRs versus those spray heads. We'll often run the MPRs about 3X that of a comparable spray pop-up zone because they put the water down at a slower PR. With a narrow watering window (often only 10:00 pm to 6:00 am) this adds overall time to the program but we've been able to double and even triple up MPR zones because of their greatly lower zone GPM.
     
  3. Remote Pigtails

    Remote Pigtails LawnSite Senior Member
    Posts: 581

    The smartline figures out the run times and it is doing exactly that. Running the MPRs three times longer. My gpm dropped from 21.5 to 7.75 per minute so the gallons used will be about the same. I guess I mentally thought a zone running at .5 in per hour would need to run twice as lond as a zone doing 1 in per hour.
     
  4. Remote Pigtails

    Remote Pigtails LawnSite Senior Member
    Posts: 581

    This brings me to another question. Water conservation is on the up swing here. So i replace my spray with MPRs. The watering efficiency factor will improve because my clay soil will be able to absorb more water because of the lower prec. rate. I'm not really using less water. My plan is to keep inching up my precipitation rate setting on the clock until I notice continuous plant stress. My point with customers is that in order to maintain the same beautiful lawn they are accustomed to we still need to use the same amount of water but we are trying to improve the irrigation system efficiency factor.
     
  5. PurpHaze

    PurpHaze LawnSite Fanatic
    Posts: 5,496

    That's the difference between the monkey analogy where just about anyone/anything can slap pipe together... but it takes a real pro to understand the plant/water relationship and put down enough water without stressing the planting material one way or the other and avoiding waste through runoff and other factors. A pro that can see and understand the whole landscape picture is well worth the extra money to hire for the job instead of a "bottom feeder" that just dumps pipe into a trench.
     
  6. Rotor_Tool

    Rotor_Tool LawnSite Senior Member
    Posts: 349

    Doesn't the Smartline controller allow you to cycle and soak so you can still use your sprays (much better DU than MP Rotators)? If run-off is the issue, why not adjust your application to a few short cycles so the soil has a chance to absorb the moisture? I haven't spent much time with the Smartline, but it seems like an inexpensive modular controller that allows marginal ET based control. I tested one based on my weather here in AZ and it really mangled run-times based on the database it draws data from.
     
  7. Remote Pigtails

    Remote Pigtails LawnSite Senior Member
    Posts: 581

    If you put in a slope factor after the soil type it will automatically run and soak.

    I haven't spent much time with the Smartline, but it seems like an inexpensive modular controller that allows marginal ET based control.

    You hit the nail on the head with this sentence. I've installed enough that I'm comfortable with it but their are early monitoring and adjustment factors that need to be done. At least it will adjust watering up or down during the season which is something I cannot get my customers to do very well.
     
  8. Rotor_Tool

    Rotor_Tool LawnSite Senior Member
    Posts: 349

    You are correct, once the customer begins making controller changes, things turn ugly quick!
     
  9. PurpHaze

    PurpHaze LawnSite Fanatic
    Posts: 5,496

    What's even worse is a principal of a school site with a key to the controller. :laugh:
     
  10. Remote Pigtails

    Remote Pigtails LawnSite Senior Member
    Posts: 581

    I'll answer my own question. Talked to the rep today. The default on spray zones on the early timers was 1.5" per hour. That was later changed to 1" per hour on newer versions. If you've never used a smartline none of this will make sense.
     

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