Flex Daily - Over watering my lawns

Hello, I have used Rachio 3 since March on my house in SoCal. I put 3 lawns in Flex to experiment (all flat/full sun). Performed the cup test, put in each value. Posts about not confusing the soak time as watering time, were read. I would typically water each lawn for about 8 minutes every other day using the old controller.

The water duration continues to be crazy high. I let it run expecting it to throttle back but it appears the same. I also noticed that the water times do not fluctuate much based on weather, though it does do a good job of forecasting rain. My expectation of Rachio was to take a baseline watering amount, then vary it based on predicted weather.

I did just manually decrease the watering duration from the system generated 40 minutes to 10 minutes to get it back to a more normal duration.

Any ideas on how I can get water consumption back to the ~2 hours a month that it was at previously and somehow use the weather forecast to change my manually added amounts?

Without knowing your zone settings, there really isn’t much we can help with. Can you post screenshots of the zone settings and advanced settings?

Just because you watered for short durations very frequently on your old controller doesn’t mean that was the correct way to water.

Ok thank you for the reply. Here are the zone settings and advanced. Only thing I changed (I think) in advanced was ‘Nozzle Inches per Hour’.

Thanks for your help!

Looks like you might have changed root depth a tad, and crop coefficient, but neither are changed enough to worry about…

Are you confident in the catch cup test you did? Do you know what type of sprinkler heads/nozzles you have? 1" per hour seems pretty low if they are a fixed spray head, extremely low if they are a variable arc spray head…

I agree, I thought the value was higher and was surprised when I saw it. (My other lawns also seemed low as well). Will rerun tests on all lawns and update.

If I run the zones in manual mode will the system take that amount fo water into consideration for future scheduling? I want to minimize water waste is why I am asking.


I guess I never confirmed…which flex? Daily or Monthly?

Any runs completed through Rachio will add to the moisture levels.

Yes. That’s one of the things I love about Flex Daily. Although you mentioned Flex, you didn’t specifically mention Flex Daily (could be Flex Monthly which doesn’t really take that into account).

That’s great. Although unusual that efficiency would come out to a round 80% and Nozzle Inches Per Hour to a round 1.00". Are those really the results from your catch cup test?

To be honest, 8 minutes per zone in SoCal sounds really low to me. Could you post a moisture graph and chart for the week?

It is daily. I re-ran the test with 3 containers for 30 minutes. There was on average 1" of water, which would be a nice round 2 inches per hour. I am wondering how .5" got in system? I thought I put in 1.5 maybe it was a typo, but i noticed my otehr lawns are also off, but not that far. I also used a different container one that is about 2" high… first one was about 4.5" high. Thinking the extra height block some water from entering on the first test.

Thanks for your help I will update the zones to the correct Inch per hour value of 2, then see how that helps.

How should I use the efficiency rate? What would 100% look like, what would 50%??

Thanks for reaching out!!

It is how efficiently the water from the sprinkler gets to the ground, so uniformity plays a big part. Usually when you do your catch cup test, there are some calculators online that can give you that figure.

Most Catch Cup manufactures & tables recommend closer to 12 cups. Depending on the area, I don’t think even that is enough. It is SOOOO very critical exactly where you put them as well as how many. Not everyone agrees with me, but I think a better method is measuring water use in gallons per minute, and area watered in square feet, and calculating a proper value. It’s not accurate for any given location, but is guaranteed accurate for the zone, if it can be measured.

Height shouldn’t matter. Location does. It’s like real estate: Location, location, location. Oh, and quantity.

Well, changing it from 0.5 to 2 will water one-fourth as long. Maybe that’s good, I can’t say. I’d be a bit afraid of it, as I think 8 minutes per zone every other day sounds very low.

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As tmcgahey said, it’s a measure of how evenly the zone is watered, usually has the definition of Efficiency = (Average Value of Lowest 25% of Cups) / (Average Value of 100% of the Cups). Then Rachio uses a complex formula of 1 / (0.4 + 0.6 x Eff) to increase the watering time. 100% would not increase watering time at all beyond the theoretical value. 50% would increase it by 43%. Unless you have obviously wet or dry spots in your zone (in which case you should try to fix them, not waste water), I’d just go with an average efficiency, and concentrate on getting the flow right.


Thanks for your help. I reset the zones based on a new cup test. Deleted the old schedule, created a new one and duration now is in the 20 - 25 minute mark for all lawns. That is in line with what I was expecting.

Thanks again,

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Damn, you work fast! :rofl: Just out of curiosity, what did you find this time around?

Nice job and congrats!

The inches per hour are about 2" per hour. I had .5" as the setting?? All working great now. Thanks!!

I have struggled with the period between waterings was too short. During early spring and late fall shoulder seasons, I just really need it to water once a week (or every 10 days) but it was constantly determined to fully water every 3-4 days because it thought the ground was dry when that was not the case. The watering duration was in the ball park but the frequency was way too often. When I looked at the water level of each zone, it showed evaporation was occurring much faster than actual (20-25% per day in mild conditions), which was prompting it to run more often. I drastically lowered my crop coefficient from the suggested 65% for warm season turf to 40% and that seems to be much more in the ballpark of actual evaporation. Adjusting crop coefficient only messes with the evaporation rate of the soil (lower coefficent percentage will reduce the amount of calculated daily evaporated water, resulting in reduced watering frequency or in other words help increase the number of days between watering).

All other advanced settings have a cause/effect relationship (ex. lowering available water capacity will result in more frequent watering but shorter runtime for that zone) but crop coefficient is the only setting that helps adjust the watering frequency without affecting the amount it waters between cycles.

I found this article helpful in explaining the cause/effect of making adjustments: https://support.rachio.com/en_us/how-do-i-edit-duration-and-frequency-on-flexible-daily-schedules-r10FDLkFw

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Wow, 40% is crazy low…for me here in AZ that is!

The 40% Crop Coefficient is what appears to have fixed my situation with the system running too much in shoulder seasons, but it is too early to tell if this is going to work for summer weather, so dont take my word as gospel. I probably will move it to 45% eventually but so far it has solved my “watering too frequent” issue. It actually rained 4 inches the past few days and I show that the system does not want to run for around 10 days which is about right for clay soil in 60-80 degree days with 40-60% humidity.

To be clear to the OP, dont go jumping to 40%, but if you are thinking you are in the same boat as me, try lowering your Crop Coefficient by 10% increments as outlined in the doc I sent and see if that helps spread out the watering frequency…