Flex schedule with long intervals

I put my grass on flex schedule. I live in the desert with very high temps so it’s normal for grass to be watered every 2-3 days. The last watering was on Sunday so 5 days ago and the grass is obviously very dry. I was letting it go a bit just to see what happens. Yesterday Rachio said it would water today, and today it says it will water tomorrow. When I look at the estimated moisture levels yesterday was 49 and today it’s 22%, so I would have expected that it would have kicked off before now. I can’t figure out what is going on, but thought I would ask before kicking off watering manually and going back to a fixed schedule.

Flex schedules will run when your moisture levels reaches zero, still within the managed allowed depletion, and before the plant wilting point. Zero doesn’t mean the crop is fully depleted of any moisture yet.


that may be the logic, but my grass will be dead by that time. I went ahead and watered manually as it was beyond dry. The University of AZ agricuture extension recommends that at this time of year we water every 3 days at least. So 5-6 is way outside the bounds of what works here. It sounds as if system is doing what it was designed to do but not sure that design works here in the desert. I think I will have to abandon flex option and go back to fixed schedule. I had high hopes for it.

It’s difficult to have them work perfectly for every situation, largely based on if input data is accurate.

This might help you dial them in if you want to experiment with a zone or two…


ok as I re read this reply I’m very confused. When I look at the zone there is a setting which is called allowed depletion. it is set at 50%, and that might have turned out to be not far off for my grass. But it seems you are saying it’s really 0%? Am I confusing two concepts? I thought that was what this value did.

MAD (managed allowed depletion) is what we allow the soil moisture to deplete to before watering again. 50% is the industry standard. Sorry its confusing above. We have to have a band from 0 - 1, so the 22% you are seeing is tracking down towards zero, which is what we’ve allowed the soil moisture to deplete to before watering again.

ok, that is confusing. I have lived in the Phoenix area for a long time. I can tell you that the observable conditions would suggest that however that algorithm is working, it won’t work here. Before trying the flex schedule I had measured output using cups and then set the frequency (every 3 days) and the times based on that data. These are the recommendations from several organizations, including the shared municipal water conservation organization that all the cities belong to. So when I went to flex, it seems to want to go to at least 6 days (that is if it really would have watered tomorrow as it threw me a curve yesterday). That’s not close at all. The system may be working as designed, but it doesn’t appear the design works here. I can go back to a fixed schedule, but think there is some logic missing in the flex version perhaps. When I read the technical explanation it all makes sense absent any on the ground observation, but it is at variance with that observation.

Ok, we really do want to learn what’s best. I’ll try to review your settings, run a simulation, and see what I come up with.

ok thanks.

I’m still trying to wrap my mind around this. So I think what you are saying is that MAD is the measure of moisture where it starts watering, and the other % is how far you have to go to reach the MAD threshold. So a measure of 50% would mean that you were really at 75% MAD.

Does this also mean then that if a I set the MAD to 75%, it would water twice as quickly? This may be a simple way around it for now. At least I think I will experiment with this concept unless you tell me I’m confused, which I may be.

oops had the math backwards. So tried 25% and it set the next targeted watering forward by 3 days.

@garmanmd, good morning. Emil here, filling in for @franz. You’re understanding the MAD adjustment correctly in your last post. Lowering the percentage (under 50%) will result in more frequent waterings; whereas increasing the percentage (over 50%) will result in less frequent waterings.

The best way to think about this is like a gas tank. As you know, at 50% your gas tank is half full; but using MAD principals, at 25% it’s 3/4 full and at 75% it’s 1/4 full.

Using MAD, you set the percentage that you want your lawn’s “gas tank” to be refilled at. Everyday we look at how much “fuel” your lawn has used and calculate when/if we’ve hit the refill point (allowed depletion). By default, we set the refill point (allowed depletion) to 50%, however this can be changed to anything from 0-100%; thus the name Management Allowed Depletion, or MAD.

The Moisture Level graphs in the web app will display the percentage of the moisture available within MAD; or how much fuel do you have left before you hit the refill point. As such, if MAD is set to 50% and your Moisture Level graph reads 50%, then your lawn’s “gas tank” is 3/4 full and will be refilled when it’s 1/2 full. Think of it as a percentage of a percentage :wink:

I hope this helps explain any confusion in the percentages you saw and provides some framework into how to use MAD as adjustment to match your lawn’s needs. If I’m understanding correctly, reducing MAD to 25% is resulting in the watering schedule you expected?

Let us know if there’s anything else we can help you with.

Best, Emil

One thing to remember as MAD goes down your irrigation amount will go down pulling down run times, so I would watch for that. You can always increase the water adjustment level in the flex schedule for each Zone to augment the watering time.

One last thing, root Zone depth has a huge factor as well. Longer roots, more irrigation time, longer days between waterings. Shorter roots, shorter irrigation time, and shorter days between watering.

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