Rachio watering schedule much more aggressive than needed

I just installed my Rachio gen 2 controller - really excited to get “smart” with my irrigation. I set up my device w/o any issues, and set up my 8 zone front/yard combined (incl a shrub/flowerbed) yard as best as I could with my limited knowledge of soil composition. I used the really helpful thread here (Using Web Soil Survey to define your soil settings) to determine that my soil on the US Soil Survey was “Ovan Clay” with an AWC of 0.18, and set the majority of my zones to:

-Warm season grass
-Silty Clay
-Lots of Sun
-Fixed Spray head
-Flat slope

I was excited to try out the flexible schedules to see how the Rachio smart brain worked, but was surprised to see it water much longer than I currently water. My current schedule: M, W, F 10 min each zone (80 min total, 240 min weekly.) Rachio flex monthly: every 4 days, 290 min total on a smart water cycle each watering day. This can mean twice a week, which is more than twice my existing watering schedule.

Long-winded way to ask, is all this watering really necessary? I’m getting nice, healthy green grass with my existing fixed schedule of 10min per zone, and I’d like to think I’m putting in all my variables correctly (each zone has an AW figure of less than 0.18.) I was hopeful that the Rachio smart schedule would help me water for less time, but it’s going the other way. (To experiment, I changed the zones to just Clay and it didn’t really make a dent in the times.)

Is there anything else I should be considering here? Any other variables I should be accounting for (ie does sq ft area matter, etc) I’d hate to just go onto a fixed plan and remove the “smartness” of the Rachio right off the bat, but it is a LOT more water than what I’m currently using for a nice green lawn.


Have you calibrated your nozzles for accurate gallons used? If not simply reduce the square footage on your zones to make the controller think it’s watering a smaller area. If you have calibrated your nozzles then you’ll also need to raise your precip rate on the nozzle by the same percentage as your sq footage reduction in order to keep your gallons used accurate.

Other possible edits:

Crop coefficient (this does NOT affect flex schedules created before 5/19/2016)
Decreasing crop coefficient decreases watering frequency

Available water
Decreasing reduces zone run time

Root depth
Decreasing reduces zone run time

Raising will reduce zone run time

Square footage is NOT used to calculate how much water to put down. It’s only use is to estimate how much water was used.


Thanks Bill, I’ll check and play around with those variables. I’m assuming that working within those parameters, Rachio still knows to work within the “water table” parameters and adjust my watering based on season and need?

Linn - does it matter what I set the sq ft to for each zone then, or is it just for the water used/water saved measure?

@johnnyma45 - @Linn is correct, the square foot value is used to calculate the displayed gallons saved/used, in combination with the rate from the nozzles and the duration.

Someone who has more experience with monthly flex scheduling can correct me if needed. I tried monthly flex briefly last year, and found that if Rachio thought one zone needed watering, then all zones in the schedule would water. I think monthly flex works best with only zones with similar vegetation and water requirements on the same schedule. You might want to try daily flex, where you can put many zones into a single schedule, but on a given day, only the zones that have reached the allowed depletion will be watered.

@jkb I’ll try that out. I’d feel more comfortable moving to a “water tank” type depletion schedule and let Rachio do the heavy lifting/thinking if I was able to get the other variables correct first - and correct to me seems to be less water, per my previous irrigation controller schedule and resultant green lawn.

Hey @johnnyma45-

Were you able to get your flex schedule to a more acceptable duration? I will say this is a common concern, flex is a new way of watering that’s often quite different than your current program. I would probably recommend reducing root zone depth and/or lowering crop coefficient if you are trying to reduce total watering! Root zone will lower duration, crop coefficient will lower frequency.

McKynzee :rachio:

In my experience, you might be interested in two variables:

Root Depth - This, combined with AWC, determines how much water Rachio thinks your soil can store. I find a deeper root setting leads to much longer runtimes, presumably to get water percolating all the way down. Deep roots are a good thing, but this effort & water is wasted if your roots are only 3". I found getting AWC & root depth right got me to roughly expected watering durations.

Crop Coefficient - Rachio seems to use different math than my local weather station. At Et0 (crop coefficient) of 0.80, Rachio comes up with much higher daily water usage estimates for my lawn than the weather station. I dialed mine down from 0.80 to 0.60, and water usage estimates (in inches) came more in line with local estimates, and the lawn was healthy. It’s not clear why this is happening. Anyway, this reduced frequency of watering to where I expected. If you can get a local watering guide on daily grass Et, you can fiddle with Crop Coefficient until your daily evapotrans in Moisture Levels roughly lines up.

I do hope the Et0 thing is eventually resolved, I was initially rather excited as my local weather station even provides a ramp of Et0 through the months, and a range for different qualities of turf, so I was going to really maximize my benefit by following them precisely! I suppose I could interpolate their numbers…

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@mckynzee, @pshyvers, I’ve continued to play around with the variables - thanks for the suggestions of root depth and crop coefficient. I’ve played around, lowered both and gotten the frequency and durations down to more reasonable figures. I’ve still had to adjust watering times manually on the last step of watering schedule creation because I’ve noticed that if I make a change to say, AWC or root depth in one zone to experiment with times, it’s affecting multiple zones around it. Does anyone know why this is?

Also, what variables do flex monthly schedules change? Duration, frequency, or both? Would my manual edits of watering times be “erased” so to speak depending on what Rachio determines as part of flex considerations?

@johnnyma45, check this article out of you haven’t already. I found it really helped me out when I was dialing things in. Make sure you look at the “Zone Attributes” table about halfway down.

I personally have one zone per schedule to keep things simple. I have a small yard so I pretty much have one vegetation type per valve anyway.

@azdavidr that article is very informative thanks. To experiment, I raised the crop coefficient by 30% on one zone, and the flex monthly changed frequency for all zones. I think to really split it out I’d have to make one zone per schedule like you.

I’ve had to fine tune the number of minutes - I wonder if month by month, this edit will change out as well.

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@johnnyma45, I use Flex Daily, so I’m a bit unaware as to how changes will affect Flex Monthly. I’m sure the trends are similar, but I’d prefer to have others with more Flex Monthly experience comment with any more details and suggestions.

To answer your earlier question, flex monthly will only adjust frequency month to month! If you want to see how the edit affects coming months, you should be able to page forward on the calendar to check it out.