The Fiction of Soil Moisture

I have been amused reading the questions about Rachio and soil moisture. Unless there are actual soil moisture sensors installed and monitored by the Rachio device, the soil moisture “data” is simply BS guesswork.
When first installed, my Rachio was set for 1) soil type; 2) sun exposure; 3) plant type; and 4) slope for the various zones in my system. Rachio proceeded to drown my yard for a month, watering as much as 120 - 355 minutes at a time in some zones and earning a warning letter from my city (Sacramento) about excessive water use. The device/system has no knowledge of the soil moisture - it is using some software algorithm to deduce a ‘probable’ moisture content. To claim otherwise, as Rachio support staff does, is misleading.
In order to change the excessive watering instilled by my installer’s initial programming, I had to edit each zone with misleading info - I told Rachio my yard was full clay soil; full sun exposure; xeriscape planting; steep slope. A couple of the zones are now a bit too dry and will need further adjustment, but most seem to be getting appropriate watering. I have no idea what the moisture content truly is - and neither does Rachio.
Rachio has taken a simple task - watering the plants - and wrapped it in a cloud of tech speak, algorithms (I just like the sound of that word) and smart phone play toys. Many people undoubtedly enjoy this. I find it a bit silly.


I respectfully disagree with pretty much everything you say, other than the part about Rachio using algorithms to calculate soil moisture, because that’s what they do…

I don’t know who set up your system, or what settings they implemented, but they were obviously wrong. I’ve had my Rachio’s for 4 years, and mine are dialed in amazingly well. Was there a learning curve to get all the advanced settings exact to match my specific yard? Yes, as to be expected. I’ve not have to put in “misleading” info to get there, I just put in actuate info. Trust me, Rachio is far from a “smart phone play toy”. I’m sorry you’ve had such a bad experience. If you’d like, let’s get your system set up correctly and see if we can’t change your thoughts?


As you can discern, I’ve been quite frustrated with the controller since it was installed the end of April. I would love to get past the complexity and water my yard efficiently, yes. My installer was proficient with wiring, perhaps not so much the programming. For me, it’s an opaque white box.

Well, let’s start with the basics…let’s get all your zones set up with the correct soil type (I’d recommend the web soil survey website), sun exposure, nozzle type (make and model of sprinklers/nozzles/drip emitters), etc.

How established is your yard, and what did your watering schedule look like before switching to Rachio? Did you water multiple times a week for short duration, or less frequently for longer run times?

Trust me, Rachio will become more than an opaque white box once we get you on the right track! :rofl:


I’m going to defend Rachio a bit here. I too initially had issues w/ the verbiage used and the percentages but once I understood where they were coming from, I get it! They are trying to simplify a very complex system. And you are right they don’t know the soil moisture w/out sensors the exception would be they know when the system is full and empty for the most part(if the information given to them in the advanced settings are correct). And if the settings are close enough the soil moisture tracks within a tolerable range to irrigate properly(I know this b/c I’ve tracked it for almost 2 months).

The good news is people like @tmcgahey and others are willing to help people understand how to get their systems tweaked and working properly.

I actually had someone in my community reach out to me via pm and ask for help tweaking their Rachio system and I spent about an 1 1/2 helping someone understand the science behind the numbers involved.

It’s not perfect but it’s the best I found for home irrigation systems.



A couple observations from my end

  1. I was with you in the beginning, moving a bit closer to the middle after about 6 months. Lots going on, and unless you are willing to re-design your yard/irrigation rather than have the Rachio fit what’s already installed, you might be chasing it a bit
  2. 120-355 mins run time may includes “soak time” if you are using that feature and have the correct head types selected. Soak time is one thing that Rachio needs to eliminate from the watering total, has been reported here and several have asked for it.
  3. Increasing slope and going full son to any zone means it must water more often b/c the system assumes more runoff and more evaporation.

My goal in buying this system was two-fold. One I like tech and wanted to automate it since I hate waking up to rain and find my system is running. And two, save water… well I’m batting 500 so far.

Good luck, don’t give up and in the long run, you might actually begin to enjoy it



I look forward to learning how Rachio works. I’ll try sharing the info discussed in the next day or two.

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What Rachio does is give you a starting point. From there it is up to you to observe and make adjustments. After the initial assumptions it is unlikely you will not have to make manual adjustments based on specific conditions in your particular application.

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I’ve had similar issues with my system. I had several LOOOONG watering times for a few zones (not including the soak time). I went in the schedule and noticed that some zones were set for long water times – I think this was done automatically as I do not remember setting them.

I backed the times down to 20-30 minutes depending on the area and the type of sprinklers (rotators need more time to water lawn than fixed sprayers).

I also have a few sections that are on a steep slope with sprayers, tons of water run off. This has been adjusted by increasing the flow rate on the sprayers and adjusting the soil type. Now they run, but also cycle through soak periods.

I have one section that is flat, has sprayers, recieves mostly sun during the day, established grass, and I know the soil type. Rachio was drowning this area. Big puddles. Here too I raised the flow rate of the sprayers. Dialing this section in when the system decides it should water this area.

I used tons of water last month, but no warning from the city…yet. :slight_smile:

I do like the weather portion of this system’s programming. The soil moisture is also beneficial, once you get all the settings dialed in (as many have said here).

I do, however, find it funny that at 10pm, it says some areas are at 35% saturated, but in the morning, with no actual rain, it’s magically at 110%. I didn’t change a thing, and the system did not run. This happened one time. I haven’t noticed it anymore.

Best of luck to us all!

I’ve seen the 110% (when it’s clearly NOT 110… in reality is much closer to 0%) a few times lately as well. Always seems to coincide when the weather station is predicting rain (although it might only be a 30% chance). I’ve wondered if the code handles the predicted rain by artificiallly inflating the soil moisture so the controller doesn’t water that night. ?? I also can’t tell you when was the last time I saw the notifications for a weather skip. i.e. - Is this some sort of ‘work-around’ for a bug being figured out in the the weather intelligence code?

If you are on Flex Daily, you rarely get “weather skips” other than wind or freezing temps. Since it is a fluid watering cycle, it is ALWAYS changing based on all the inputs, so it doesn’t really “skip” in the same sense as other schedule types, it will just adjust, and push out a watering.


And I repeat - the Rachio device cannot measure your actual soil moisture. It is capable of one task only: opening water valves at specific times and closing them later. The soak cycle? Brilliant, a great innovation. The rain/wind/etc. skips? Nice use of weather data to predict potential overwatering. Having to go to school for hours on end to re-learn how to water my yard? Not so great. It’s not nearly so complex a concept as all that.


I still don’t think it is as complex as you think it is. It’s all about understanding what you actually have in your yard, and giving that information to Rachio, so it can do what it does best. There are HUNDREDS of sprinkler nozzles out in the market, each with a unique precipitation rate. Once the other defaults are set, this is the one area I think most people have issues with. If you select spray nozzles and leave it as the default setting, but you have Hunter Variable Arc Nozzles (still a spray nozzle), these are rather inefficient IMHO, and you might be putting down 2-3 times the amount of water that Rachio thinks you are.

@Sacramennah, maybe I have missed it somewhere, but have you posted your system setup yet for us to take a look at? I’m ready when you are!

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Yes, I’m using the flex daily… Are you sure about the ‘constantly’ changing? I remember Support telling me in a ticket that it all happens at midnight. Although, I have noticed that the ‘fixed schedule’ plans are the only schedule that gets adjusted automatically by weather intelligence according to the season.

I’d also like to better understand the sudden 110% moisture level when it was recently (and still is because it has yet to rain and hasn’t been irrigated) at only 30x%.

You are correct, it checks at midnight, and also 1 hour (I believe) before scheduled watering to make sure nothing has changed in the forecast.

Was this 100% spike recent? Are you able to still see it in your moisture graphs? Curious if the PWS you are pointing to had an erroneous reading…

Not recent enough for that, no… last time the 110% issue occurred was a week or two ago. Actually, the most recent unexpected moisture reading (last thurs or so) went the other way - down to 0%… but for just two zones (vs all of them showing the 110%). The two zones had just watered that morning and were probably about 50% in reality… I just let them water again that night since they’re out along the curb where the road likes to cook the lawn. The moisture levels are back to ‘normal’ over the past few days.

Erroneous - as in it reported that it rained when it didn’t? I’ll have to click through and look at the station’s actual weather data when it happens again.

Hi tmcgahey -
Yes, I’ve been distracted with other issues. How exactly would I go about posting my system setup?

Screenshots of your zone settings (both “regular” and “advanced”), and a rundown of your equipment (sprinkler or nozzle manufacturer/model) would be a great start!

I should mention that the controller seems to be functioning satisfactorily - nothing is flooding, nothing is dying from drought. Main reason the urgency has abated for me. I do get odd random notices - “Rachio has started watering courtyard at x:00 AM” for instance, when it did no such thing. Curious.

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It’s possible. Rachio pulls the data from the vast network of public and private weather stations, and sometimes the private ones, and sometime the data recieved from these weather stations can get messed up.