Help me with flex configuration please

Hi folks - so I have a lawn that’s roughly 600sft. Currently it has 3 sprinkler zones, see pic. I roughly drew a circle around what each sprinkler covers, and the 3 different colors are the 3 different zones. The zones were set up by the previous owner. They are all rainbird rotary nozzle heads, 1800 PRS-30.

I have been doing manually scheduled runs but I want to try out the flex schedule to improve that dry grass patch I have and also just take the guess work out of this.

I have figured out my soil type (clay loam, I am in northern CA bay area) and have catch cups ready to go for a test, but first I want to come up with a plan.

For my catch cup test:

  1. Should I run each zone independently, measure the catch cups, and then try to put in nozzle in/hr such that I am not duplicating one zone with another? Meaning if zone 1 gets me 1in/hr and zone 2 gets me 2in/hr, and they overlap perfectly (so 1.5in/hr avg), then I’d put in maybe .7 for zone 1 and .8 for zone 2?

  2. Same question for efficiency - how would I calculate / tweak that given the overlap in zones?

Thanks in advance

Am I correct that there are 9 sprinklers in this small space? What kind of nozzles are on these sprinklers? Seems a bit excessive to have 3 zones for this small area. If you don’t have a master valve on your system, I’d honestly combine the 3 zones into one by wiring them all together. That is what I did with my yard. I switched all my nozzles to Hunter MP-Rotator and managed to turn 14 zones into 6 zones for grass. With the lower flow of the MP nozzles, some of my bigger zones are well over 15 sprinklers, and works awesome.

Otherwise, if you want to keep them all independent, just make sure that the settings are all the same in order to make sure that they all run on the same date. When doing the catch cup spread over multiple zones, you need to run each zone for equal time to account for the overlap.


Thanks for the helpful reply. There are 10 sprinklers actually. I agree it’s a bit excessive. To add to the headache, each of the 3 zones is also hooked up to a different drip line. My plan was to combine all 3 spinkler zones into maybe 2 zones (more sunny vs more shady) and then put all the drip lines on the 3rd zone.

Your reply helped me with my test strategy - time to execute.

You may have issues with pressure with everything on at same time. You should be able to manually turn on all the valves (physically turn on each valve, not using software).

I personally would keep them separate, the work is already done.
As for measurements, you’re basically adjusting for worst area in a zone. But consider shade and other things. Get your ballpark settings in there, and then I keep moving the Coeff down until my grass was turning brown in a summer heat, then bump it up a bit. If you get mushrooms growing, bump it down a lot (like 15-20%).
There are lots of approaches to fine tuning everything.

That’s why I mentioned switching to MP’s…

When I went from 3 zones full of high flow spray heads to 1 zones of Hunter MP Rotators, I actually had to dial back my pressure to keep the MP’s in their happy range of about 40 psi. The MP’s put down a fraction of what the old inefficient VAN’s did. The zones run for longer times, but the spray is way more uniform and I have zero pooling or runoff now.

say, if the mp run 1/3 flow at 3x time vs 3x flow at 1/3 time am i missing something about savings ?? or is it just the coverage is better, with smart cycle not sure i have pooling or anything.
debating swapping a zone from conventual sprays to mp.

You are dead on. It isn’t really about savings in the way that they don’t magically make the grass need less water. When you adjust the PR in the settings, Rachio is still going to want to put down the same amount of water. What I noticed is MUCH more uniform coverage between heads, less susceptible to small winds (larger water droplets vs. fine mist) and less pooling in areas of my grass. True fixed spray heads are better than VAN spray heads, but you can always see areas within the arc that get way more water. MP’s seem to have an identical pattern regardless if you adjust 90 degrees, or 270 degree arc. If you had slopes, the much lower PR of the MP’s would help to eliminate runoff as well.