Precip and Soil Moisture readings seem wonky-

Hi! This is only my 1st week with the Rachio 3, so please forgive any newbie mistakes/ignorance. I’m seeing some weirdness with my precip levels and how it interacts with soil moisture. Current situation:

  • It rained heavily last night (~12 hours ago). My PWS is accurately reporting 1.1". WI+ reports .89". Close enough.
  • I have 3 zones (1 front yard, 2 back yard, each zone 750sq".) Most advanced settings are similar. Front yard is 1 year older, so its roots are slightly deeper (5" compared to 4" in back yard), nozzle inches/hour also vary from .4 to .6. Zone 3 gets more shade.
  • When I set the controller to use my PWS (reading 1.1" precip), the zones show the following soil moistures: 19%, 9%, and 34%, respectively. When I dig down into the soil moisture menu, zone 1 is only showing .01" precip, while zones 2 & 3 correctly show 1.1".
  • When I set the controller to use WI+ (reading .89"), my zones show soil moisture of 31%, 24%, 49%. Precip still shows .01" for zone 1, but zone 2 & 3 correctly show .89".

These last 2 points are the kicker. Why would a reading of more rain equate to lower soil moisture? And wouldn’t 1.1" of rain fill everything up to closer to 100%? Also, zone 1 incorrectly reads .01" of precip no matter what, yet the soil moisture % changes?

What am I missing? Thanks!


Additional Edit: Sandy soil, warm weather zoysia, South Carolina.

What schedule type fixed, flex daily, or flex monthly?

Flex Daily.

I checked mine and they were all the same. I’ve never experienced that maybe someone else will step in and help answer that question.


Couple quick things:

  1. Your zone available water capacity is really low due to choosing loamy sand for your soil type.
  2. The soil moisture graph is not reporting a lot of precipitation. Are you sure the chosen station is reporting correctly?


Hey @franz! Thanks for the response. It makes sense that with such a sandy soil, the AW is low. I imagine the shallow root depth settings also contribute to that?

As far as your 2nd point, I’ve attached a composite screenshot showing you both zones 1 and 2, with both my PWS and WI+ settings. I’ve circled the things I think are wonky. Thanks!!

Edit: What you’ll see on the image is that the PWS is reporting correctly on Zone 2 (also zone 3, just not pictured.). You can also see the PWS reporting correctly here:

For some reason zone 1 is just stubborn and doesn’t see it. The soil moisture readings, however, seem to go down up when less rain is reported from WI+ than the PWS. Strange, right?

Yeah now I see it. Reviewing with engineering team.


Whenever you fill or empty the soil moisture for a zone that effectively wipes out any data to that point in time. It looks like for zone 1 your emptied the zone hence emptying out any precipitation data.


Ah. I feel dumb. I do seem to remember hitting that on accident at some point. That explains the weirdness with Zone 1.

+1 for the ability to manually set a soil moisture % instead of just fill/empty.

However, is it still correct that the % calculations drop when more rain is detected?


I know this gets brought up from time to time, but in reality, is it really a big issue? Yes, in this case it cause some confusion, but when you empty of fill, you’re affecting things for less than a few days, and things are right back on track.

Haha…fair enough. At the end of the day, of course it’s not a big issue.

Life was just fine before internet enabled sprinkler systems existed. Now that they do, the desire to tinker and make them smarter continues.

Certainly there’s no need to adjust the soil moisture % just for the hell of it. But if Rachio thinks my yard is sitting at 110% saturation, and I pull a plug and deem to to be at 50%, I think the system could learn from that info. Granted, a soil moisture meter embedded in the soil would solve all these issues…