Flex Monthly refuses to water

Hey Rachio SMEs,

I’ve been using Rachio for quite a few years now, but it constantly seems like Flex monthly is getting more and more and more and more conservative on watering each season. I’m at the point where Rachio wants to water for 6 minutes each zone (rotor heads) each day. With the droughts going on, and 90F+ back to back weather each day, my yard is becoming absolutely fried. I constantly find myself having to manually add runs each day, but Rachio seems to be adjusting for that and setting the zones to run even less and less time.

I’m not sure what I’m doing wrong, I’ve set all my zones to the proper heads, soil type, “lots of sun” for the zones that have no shade, and have now set the allowed depletion to 30%. Each of these changes seem to be making things worse rather than better.

I’ve gone as far as purchasing a PWS and leveraging that so the system knows exactly how much rain is hitting my yard and can calculate exact evapotranspiration rates.

I’m at a loss on what exactly to do here, any thoughts on how to make it so this thing waters for much longer durations?

Thank you!

A screenshot of the advanced settings might be helpful. What is your root depth? What did you change your Allowed Depletion from when you set it to 30%? With the correct heads and soil type, do you have the correct nozzle rate and available water?

Here’s what I have. Most of my other zones are the same except area. Depletion was at 50% on some zones and 45 on others.

I just noticed the 6 minutes is each day vs every other day now, but that seems like it would be worse than saturating the yard every other day.

A couple of thoughts:

Dropping the Allowed depletion down is going to cause your system to water more often, while still putting down the same amount of water per week – more water, less often is actually probably better for your lawn, so I’d put your allowed depletion back up.

Do you have any watering restrictions? If not, I’d seriously look at going to Flex Daily instead of Flex monthly. The problem with Flex monthly is that it looks at historical data instead of data happening now. So if you are having drought conditions this year that aren’t normal for you, you are probably not watering enough. Flex Daily will tune to what is happening now.

Yes, once you’ve put down the water manually, the Flex schedules now don’t think they need to put down more since you chose your own time when you wanted it to put the water down.

I would really double check your nozzle inches per hour. That makes a big impact. And you might consider upping your crop coefficient. Give it a try at maybe 80% and see what it does.

That all said, it’s really not best to change everything at once. It’s better to just change one parameter at a time and watch what effect it has. In your case, as long as you don’t have watering restrictions, I think I’d change to Flex Daily, but also definitely check those nozzle inches per hour.

Appreciate the response! No watering restrictions, so will try giving the daily a shot and see if Rainbird knows the nozzle amount.

As a feature request, Rachio should really start building up a database of heads. Then as an end user I can say I have X nozzle/bubbler/etc and it automatically uses the correct values instead of me guestimating or hunting down PDFs :smiley:


Took a look at the rotor specs… what should I put down, seems like a massive variance on in/hr lol


Precipitation rate: 0.20 to 1.50 in/hr (5 to 38 mm/h)
Radius: 25 to 50 feet (7.6 to 15.2 m)
Radius may be reduced up to 25% with radius reduction screw
Pressure: 25 to 65 psi (1.7 to 4.5 bar)
Flow Rate: 0.76 to 9.63 gpm (3.0 to 36.6 l/m; 0.17 to 2.19 m3/h)
Reversing full- and part-circle adjustment from 40° - 360°
Standard nozzle trajectory of 25°. Low angle nozzle trajectory of 10°. MPR nozzles varied nozzle trajectory between 12° - 25°.

Your best bet is to measure it. Rachio doesn’t know if you have 3 heads for a zone or 30 heads for the exact same zone – and they don’t know your water pressure. Or if you have a mix of different ty[pes of heads on a zone (yes, it happens). So they take an average stab at things, but it’s best if you figure out your own unique situation. Here’s a good post for a methodology that should get you dialed in:

Also, this is a really good read (written by another user) to help you understand all the settings and their effect on things.

I know that Flex Monthly has often been recommended for people who want predictability in their watering schedules, but getting these settings close is equally as important for any of the Flex schedules. Taking time to work through them the first time can seem overwhelming, but once you get them it becomes pretty simple. Just do them one at a time and see what happens.

Hi Stromb0li,

Here are my humble suggestions and forgive me if you have done this or know it:

Make sure the rotors’ sprinkling arc reaches the next rotor device. (head to head coverage)

Test your soil’s texture or have it tested. If it’s clay, the water is running off and not being absorbed into the soil. Set Rachio to “cycle”. Water for a short time, wait for it to soak in and water again. In clay, 2 minutes of spray/rotor irrigation may take an hour to soak in.
Below is my cheat sheet. I have made any mistakes, Rachio, please let me know.

H2 XERO LANDSCAPE: &[Date] &[Time]
Rachio Non- Advanced Settings
Zone Attribute Notes
Zone Type of plants grass, vegs, xeriscape etc. Most plants have typical water needs. Your Horticulturist-Designer will know the exceptions.
Spray Head or Drip Line Type/method of irrigation Spray type, or Drip type
Soil Type/Texture- not pH Test your soil Soil texture is a major factor in how fast water gets to the plant roots. Sand fastest & clay slowest
Exposure- Sun Shade etc. Full sun+6-8 hrs., Part sun/Some shade= 4-6 hours of sun, Lots of Shade/ filtered through leaves= 2-4 hrs. of sun, Mostly shade=under house eaves, on North side, dense shade under trees More sun increases the watering frequency
Less sun decreases the watering frequency
Slope Flat= water stays there, Slight= water seeps down hill, Moderate= water flows down hill, Steep= you can not walk on it without falling. The greater the slope angle that more run off. The bottom of slope gets most of the water & probably too much unless you cycle the irrigation so it waters for a short time, rests to allow water to soak in, then waters a little more, etc. It waters the same amount of time but spread out over a longer period of time. Extremely important on clay slopes.
Zone Attribute Run time Frequency NOTES
Area Sq. Ft does not affect irrigation. It shows water saved in a zone.
Soil-Available Water capacity (AWC) Increasing extends run time Increasing reduces watering frequency
Decreasing reduces run time Decreasing increases watering frequency
Crop root zone depth (RZD) Increasing extends run time Increasing reduces watering frequency
Decreasing reduces run time Decreasing increases watering frequency
Management allowed depletion (MAD) Increasing extends run time Increasing reduces watering frequency
Decreasing reduces run time Decreasing increases watering frequency, and maintains more water in the soil.
Efficiency 90% DU efficiency decreases irrigation. Lower efficiency increases irrigation
50% DU efficiency increases irrigation floods the area to make up for poor nozzle coverage.
Crop coefficient Increasing crop coefficient increases the watering frequency For Vegs
Decreasing crop coefficient decreases the watering frequency For Low water plants
Nozzle type- see Mfg. charts for inches per hour. Increasing in/hr. reduces run time SPRAY- Find precipitation rate (Inches per Hour for spray) in Manufactures charts
Decreasing in/hr. extends run time DRIP- Find precipitation rate (Inches per Hour for drip) in Manufactures charts
Soil Moisture- when to fill or empty Increasing tells Flex Daily to water less the next time. Fill if the soil is too saturated-
Decreasing tells Flex Daily to water at the next opportunity Empty if soil is too dry. Set on empty

I hope this is helpful.