2016 Flex chronicle (aka eating your own dog food)

If you don’t remember the great flex wars of the 2.5 software release, I’d rather not open up fresh wounds, but document my personal story using flex schedules this year. Last year I tried, I really did, but had a hard time dialing them in, and I wrote a lot of the software. That alone has to tell you something.

New year, new perspective, new functionality. Let’s eat our own dog food again.

A little back story of my experience last year. Colorado had significant rain totals in all of May/beginning of July and flex worked wonderfully. Not watering for weeks at a time. What voodoo have we introduced into this world where it adjusts real-time based on Mother Nature’s whimsy? Things got more difficult when July weather hit its stride and things really heated up. I wanted a bit more water time, but not much, and increased frequency. The only simple tools at the time were adjusting the watering duration in large increments and changing characteristics that were inherently correct, but needed to be changed anyways, just to adjust watering frequency.

This year we allow for much finer grained watering duration control (+/- 5% increments) and allow customers to modify the crop coefficient, which is by far the best and easiest lever in adjusting watering frequency.

Now mind you the adjustment tools aren’t perfect, and will get simpler and more powerful, but are better than last year.

The following will be a chronicle of my personal usage of flex schedules during the 2016 watering season. I plan to document my yard health as often as possible and also document any adjustments I end up making to my individual zones.

I’m visitng California at the moment, and live in Colorado, and am still amazed that I can setup and fine tune my flex schedules from over 1,000 miles away.

My only ask is please don’t seek help in adjusting flex schedules from the Rachio support team. We simply don’t have the staff to individually assist everyone out there in irrigation land. Hopefully, there is enough documentation and community support to help in this area. If you believe there is a defect now that is another story, and we do appreciate those reported :wink:

Chronology will follow below as replies. I’ve made this a closed topic so as not to take away from the chronicling flow. If you have any questions please reference in a separate topic so as not to take away from the flow.

:cheers: :colorado:


Week of May 30th, 2016.

I’m going to start with one backyard Zone since i think it is indicative of my entire yard. My back two zones have identical characteristics, my front yard has the only difference of being shaded a large part of the day. If they start to stray wildly, I’ll pull them into this chronicle.

The characteristics for Zone 2 are shown below. This seems typical for Colorado.

I’m lazy and haven’t done a catch cup test, but think I know in general how many minutes my zone needs for deep watering, since I know roughly what the nozzle output is. I chose a rotor head, even though at 1in/hr of precipitation its high considering I have impact nozzles, I’ve adjusted the watering minutes down by 30%. I probably could/should have created a custom nozzle but I didn’t feel like it. Do as I say, not as I do :wink:

The system ran the flex schedule on Friday June 3rd since I created my schedule Thursday June 2nd (at night).

…and is scheduled to run again on June 8th (but probably before since June 7th is so low, and the predicted .17in of precipitation on June 6th will more than likely not materialize fully).

The more I use flex scheduling and look at these graphs, the more I question our desire to remove it with something simpler, but less powerful. I’m proud we’ve built what we’ve built, and can’t wait for more people to fall in love with it, while the whole time saving incredible amounts of water while helping yards get healthy.

:cheers: :colorado:


Week of June 6th, 2016 Part I

If you remember from last week Zone 2 (Back North) was targeted (predicted) to water June 8th. We had a really hot weekend and the flex schedule ran for Zone 2 this morning (June 6th). This is actually very normal for Colorado, watering every 2 or 3 days in June. The observed Crop ET from the last few days is higher than forecasted, so we watered based on soil moisture depletion. Very cool how the system is dynamically tracking these weather changes and will adjust every day accordingly.

One other thing to note is my Front yard zone (Zone 3) has tree shade so will water a little less frequently than the 2 back yard zones since I’ve changed the sun exposure on it. Sun exposure directly impacts crop coefficient. Less sun exposure, less crop coefficient.

Some shade

Instead of watering on June 6th when the two back yard zones did, the front yard zone will water tomorrow June 7th.

:cheers: :colorado:

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Week of June 6th, 2016 Part II

We received .1 inches of rain last night (observed), and forecasted for another .1 inches of rain so my Front yard (zone 1) was delayed for another day (pretty cool!).

Note I changed my PWS to something that seemed more accurate. I ordered a PWS today and can’t wait to start using my own weather station to guarantee the data validity. This exercise also emphasized how important accurate weather data is for micro-climates. We are currently looking at how we can augment our existing PWS footprint as well as get more accurate and timely precipitation data. We do understand how important this data is.

:cheers: :colorado:

Going to follow this thread for installing my PWS.

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Week of June 6th, 2016 Part III

Back yards zones watered on the 6th of June and still look good. We received rain on the 6th (night) and 7th which have helped keep their moisture levels up. I changed my weather station to get more accurate precipitation and did notice a considerable drop in Crop evapotranspiration which means it is going to take longer to water till the next cycle. Really curious to see what happens when I get my weather station running.

One thing I did recognize, excluding precipitation, is once you have your settings dialed in, as long as you continue to use the same weather station, everything becomes relative. If your station under reports temperature and humidity, you probably compensated in zone settings, and vice versa.

:cheers: :colorado:


Week of June 13th, 2016 Part I

Things are still looking good. The last time I watered was June 6th, and the next predicted watering is June 16th.

We had a crazy hail storm today which is reflected in the .46in of rain on the moisture graph.

It still seems like my forecasted ET is typically higher than the actual observations. If that continues when it gets really hot I’ll probably just compensate by increasing crop coefficient a bit. At the end of the day this whole system is based on observation from your chosen weather station. As long as you get the system dialed in accordingly to the weather station you are using, everything else will just work.

:cheers: :colorado:


I figured out why the forecasted ET is always higher for my location. The forecasted wind speeds are usually significantly higher than the PWS station is reporting.

Some items to note about wind speeds (thank you Tony from Aeris weather for this information)

  • The observed and forecast wind speeds are for a height of 10 meters.

  • While official stations such as Airports will provide a true 10 meter height wind observation, it is hard to guarantee that Personal Weather Stations accurately have their anemometer at 10 meters and in a non obstructed area. If the anemometer is lower in elevation or have building trees near by, it could cause the observed wind speed to be lower than the official station observations.

  • Many PWS and/or 3rd party PWS software will allow for adjusting the wind speed value to simulate 10 meters if the anemometer is at a lower elevation.

So, further strengthening the fact that highly accurate weather data plays a big part in the system determining evapotranspiration.

This goes back to my statements above regarding adjusting your zones accordingly. If the station I am using generally has lower wind values than the forecast (you don’t need to know that, just that observed ET is lower than forecasted), I can adjust the crop coefficient a little bit higher to compensate for that (if the yard needs slightly more frequent watering).



Week of June 20th, 2016 Part I

So far things are still looking really good. I’ve only watered June 3rd, June 6th, June 17th and June 20th. 4 times for the month.

Things really heated up last week (almost 100 degrees on Sunday) and I wanted to get ahead of flex (last year I got too far behind it) as I could start to see when things got really hot the days in-between waterings a little long for my liking.

Also, I think having the clay loam soil type was a little generous for my soil in Golden, CO. Clay loam we have defined with an available water capacity (AWC) of .2 inches. This equated to .6 inches of water applied to my yard. This means that we need .6 inches of ET (after the crop coefficient is applied) to water again. Looking at my moisture chart, seeing an average of .15 inches per day of ET on hot days, I just felt that the soil AWC needed to be lower.

I switched the soil type to silty clay which has an AWC of .16 inches. If you look at my irrigation from today we applied .48 inches of irrigation, which feels a bit better. The watering duration went down a bit, but the frequency will go up a bit, since it will take less time to empty .48 inches, versus emptying .6 inches.

I’m going to let this run for a week or two and if I see the yard getting too much water I might lower the crop coefficient (which will pull down ET less), and if it is getting too little water I can increase the crop coefficient a bit (which will pull down ET more).

:cheers: :colorado:

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Week of June 27th, 2016 Part I

Things really heated up last week and my lawn was struggling a bit so I raised my crop coefficient to 85%. I think that will get me through the summer, if not I might kick that up just a little bit more.

For the month of June flex watered my front zone 6 times and my back zones 5 times. Pretty good for Colorado! I like to let the lawn get a little stressed, but nothing really noticeable. Some of my neighbors run their systems twice a day, every other day, and while their lawns look really, really lush, I can’t imagine how much water they are putting out, and I guarantee my lawn is actually healthier with cycle soaking and infrequent (as possible) waterings.

We just got some rain last night (flex deferred watering) and will get more today.

I really do believe this is the way to water. Yes, it does take some time to setup initially and monitor through the hot months (until you understand how they system works), but I think it is very rewarding seeing the results of your effort.

:cheers: :colorado:


Week of July 25th, 2016

Almost through July and the yard is still going strong. Temperatures really hockey stick in July out in Colorado and things get dry extremely fast. Last year flex daily scheduling fell over for my yard and I didn’t have an easy way to compensate. I ended up not using it through July and just used a fixed schedule.

With the addition of being able to edit the crop coefficient things have turned around (which is by far the easiest way to modify watering frequency). My front and back North zones are at 90% crop coefficient, back South zone is at 80%. Watering is every 2-3 days.

Here are some pictures from the zones.

Front North

Front North

Back South and Back North


I feel confident now surviving the hottest time of the year that the back half of the watering season will be for the most part already dialed in.

The coolest part is seeing my PWS in action. I was out of Colorado last week and it’s so great to see flex daily automatically adjusting itself due to some fairly large thunderstorms we received over the last two days (.16 and .30 inches of precipitation) and the zone moisture levels essentially getting topped off. That’s a significant amount of precipitation that may not have been recorded with a weather station that was outside of Golden, CO.

Here are the settings for my zones.

Front zone

Back South zone

Back North zone

:cheers: :colorado:

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Week of July 25th, 2016 Part II

Really cool to see real time flex in action. At 7:30PM I checked my flex daily and my front and back zones were scheduled to run tomorrow as the zones were going to be depleted.

At 9PM an intense thunderstorm came through and we received .42 inches of rain in about 40 minutes.

Now the zones are full and watering will be deferred for 2 more days.

Flex daily for the win!



July 2016 Wrapup

Last day in July and I wanted to provide a wrap up for the month.

I had to total up my zone runs three times because I didn’t believe the numbers for the month of July.

My front zone by tomorrow will have been run 9 times, back North zone 8 times, and back South 7 times.

Normal watering in Colorado for July would be around 12-15 watering times.

My water savings compared to a simple set and forget schedule ranged from about 25%-50% (front to back zones).

The one thing I did notice is there are a couple stressed grass parts on my zones that were exclusively due to nozzle placement (or non-placement). The cheap impact rotors I use are far from the best way to irrigate. I don’t have the most efficient system in place (It’s not even underground, I just use 3 hoses). Irrigation setup plays just as an important factor as does dialing in your zone characteristics.

We have a little over 2 months in the Colorado watering season, curious to see how August and September go.

Hope this is useful to see a real world example of running flex daily.

:cheers: :colorado:


August Checkin!

Flex daily continues to amaze me. I haven’t made any adjustments since early July and still going great.

We’ve had a couple significant rains this month which pushed out my watering quite a bit. This week we are having a cooling snap and some rain over the next couple of days. I’ve only watered 5 times so far this month! The way my moisture graph is showing I will only water 2 more times till the end of the month. I almost think it will only be once more looking at the weather for the next couple days.

I watered on Monday, we received rain today, and I’m not scheduled to water until the weekend!

At the end of August, beginning of September I’ll have another followup.

Hope to close the season out really strong (by not watering :wink: )

:cheers: :colorado:

September Checkin!

I tallied up September waterings for my Front zone and the total came to 8.

There was close to zero precipitation in September and we had a little warmer temperatures than normal.

Still great that I averaged twice a week watering :wink:

I’ll report when October is finished and that should wrap it up for the year!

:cheers: :colorado:

Thought would be fun to bump this up for the curious.

Franz dimelo. I think I could learn a couple of things from you to since I heard that you are the kings of flex daily schedule

Not any more, @theflexdude is the new king :wink: