When I go through all of the advanced zone settings precisely and then look at the advanced schedule duration i can see the total and individual zone duration. In there i can edit the duration. What i can not figure out is when i adjust the duration on a zone, nothing in the zone settings changes. For example if i change one of my grass zones from 18 min to 14 min, i would expect to see something like the nozzle rate change from 1.5 inches per hour to 1.7, but i dont. I do not see any changes at all.
I am fairly sure that the reason is that a zone can be in multiple schedules, and this is some sort of correction to the default based on the zone settings, but it seems that the adjustment should be visible between the zone and the schedule or have some indicator of adjustment from the default. I dont even see a bulk reset to default, that would read the settings from the zone data. What happens after i adjust the duration and save it, i then go into the zone file and make a tiny adjustment to the nozzle rate, does it reset the schedule duration back to default for those settings, or does it try to use the correction to the duration in concert with the new irrigation rate? You can see the problems that arise.
I did a bit more experimentation. Changing the zone settings after duration changes does not reset the time to a default. It does however continue to change them. This looks to be an offset in the schedule, with no way to see or reset it do default. As far as i can tell, the only way to get the duration back to the default for the particular zone irrigation rates is to set up a new temp schedule for the zone and then look at the duration. From there the old schedule can be reset to the default duration and then the temp schedule deleted. Then adjustments to the zone variables can be made while keeping an eye on the duration times (but dont change them directly).
In the end, human manual tweaks are needed to calibrate the system to reality from time to time, as it is only a crude model of the real world.
It should change them to the calculated values based on whatever the zone settings are. Any given set of zone settings has a calculated watering time associated with it. You can calculated it yourself given the formulas:
Root Depth x Available Water x Allowed Depletion / Nozzle Inches per Hour / (0.4+0.6*Efficiency) x 60
where Allowed Depletion and Efficiency, normally given as percents, are expressed as decimal (0.50).
That value should/will come out to the same number of minutes each time it’s calculated. Oh, I didn’t include the adjustment for Shade; the above is for full sun.
As mentioned, you shouldn’t have to do that. If you want the default values for the Advanced variables, there’s a link to do that at the bottom of the Advanced screen. But given a set of Advanced variables, time should always be the same.
Manual tweaks are best done elsewhere, not on the times. If your nozzle inches per hour setting isn’t accurate, it can and should be changed (easier said than done to determine sometimes, though). If you want more water applied at one time/day, increase the Root Depth or Allowed Depletion. If you want more water applied over time, week to week, increase the Crop Coefficient. Those will give you what you want, and the times will be calculated accordingly.
I agree that it should work that way, but it doesn’t. You should try the experiment that i will describe below. It should take a duration correction, convert it to a decimal & display it somewhere. When you change any variable in the zone settings, this number should return to 1.0. It does not do that.
take two identical grass zones, one is the control, one the test subject (DUT). Adjust the DUT duration by 50% and save/refresh the file. Return to the advanced settings and change the inches per hour by 50% and save/refresh the file. return to the advanced zone settings and return the inches per hour to its original settings (as is in the control zone). Compare the duration settings of the two zones. they will not be the same. You can try various versions of this test, and they all seem to be a bit screwy.
As for the equation. That seems about right, if you add a correction of about 80%, but i am uncertain due to the screwed up duration that i now have due to the above tweaking. I do not see any changes in duration due to sun/shade. I think that only affects ET, and thus the watering days in a month, not the duration per cycle.
I agree, but I think this is a bit more complicated. The most important manual tweaks come from measuring the soil, and secondly the nozzles (inches per hour and efficiency). measuring the moisture depth in your soil a few hours after irrigation tells you if things are correct. It is more complicated to determine what variable in the model needs adjusting to correct the discrepancy. For example if you think you are watering 4 inches deep on a cycle and 6 hours after watering it is saturated 8 inches down, you are way off, assuming less than 20% hydration prior to testing. Measuring efficiency of sprinklers is very complicated, especially if wind hours are factored in. Inches per hour with no wind and with a 5 mph breeze for every square meter and averaging and taking into account the minimum and maximum variation leaves you with a lot of data that you dont know what to do with. The most important thing is moisture content of the soil right after watering and just before watering. I believe that measuring it and making adjustments (preferably not to the duration section directly), including disabling the zone for a while, is needed to get optimum results.
There is no substitute for good human intervention into emerging AI systems. Trust but verify. You cant fix what you cant measure.
If I understand this correctly, you’re taking a zone with all its settings, CHANGING the duration first (eliminating any calculations done). Then change the inches per hour, and save. And changing the inches per hour back, and save. Of course they won’t be the same duration, after /either/ of the changes, because you started with a manual duration. Any manual changes you make to duration will never be duplicated after doing any zone changes, except by accident.
No correction should be required. I’m guessing you’re not including the Efficiency in the calculation. In my spreadsheet, all the calculated times agree with the actual times within a minute, due to rounding.
That is correct.
I agree the most important variable to get right is the Nozzle Inches per Hour. Unfortunately, my figures differ by over 50% to what is given as the default. Also, unfortunately, it can be difficult to determine this. My catch cup test was a bust, as the efficiency is so low that getting an accurate average is impossible. I use the Area vs GPM method, which works well for me (and IMHO most anyone who can measure area fairly accurately). Efficiency is less important, as it simply overwaters to make up for possible dryer areas, but you can see them, and if things look even, not worry about it too much.
I actually don’t think that matters much. With Rachio Flex Daily, you’re putting down X.XX inches of water per day on average, based on the Crop Evapotranspiration, which is determined by the weather (including sun/shade) and the Crop Coefficient. Very simple, and pretty accurate, given an accurate Nozzle Inches per Hour value. All the rest of the factors (basically Soil Available Water, Root Depth and Allowed Depletion) simply calculate how much water to apply at one time, or rather during one day. Too much, and it will tend to run off. Increase it and Flex Daily will water less often. Decrease it (but not below daily ET), and Flex Daily will water more often. It’s not that critical, but Rachio’s values give good results, I think, to promote good root depth. Any method assumes the soil is saturated at first, down to at least the root depth; after that, you’re just working with the upper half.
True, but not sure it matters that much. You can’t figure in wind, not knowing the speed or direction.
With the right kind of moisture gauge, that might be good (most don’t read /real/ moisture by depth, which is required). But again, it doesn’t matter much: Put the right amount of total water on per week (pretty easy), and for lawns at least, only water every 3 days or so, depending on temperature. Flex Daily using the given values does that. For me, anyhow.
@rraisley You are correct in your interpretation of the test. What the controller should do and what it does differ. It is good that it gives you a brute force manual control over individual and group time, but you should see that change and it should reset if you adjust or refresh in any way the zone values. you could always go back and adjust it again manually. In my case, if i run the duration calculation that you posted, i get 20.1 min. If i set up a new zone, i also get 20 min, so the equation checks out (although i am a bit mystified in the needed odd correction to efficiency with the 0.4 + 0.6*eff. My zones that use these settings in the same schedule show 16m. I can change it back to the “default” of 20m, but i see no way besides the way i mentioned by creating a temp zone (or now with the equation behind the duration that you posted) to get the value and then manually change it to get it to the default of the calculation. You should play with the sequence that i laid out and see some strange changes in duration. You will see what i mean.
I have found that using an 8 in soil probe every day in several locations for several days tells the real story better than simple catch cans and moisture meters. Water doesn’t tend to run off here, it just either saturates further down in the clay layer or is a waste of money past the 4-6" root zone.
You seem to think that once you’ve made a manual change to the time, that the schedule should take that into account in all previous settings or calculations. I don’t think so; it tells you its calculated time based on your settings, and that shouldn’t change. Although I do feel that there ought to be a message on the Run Minutes telling you that changing times overrides the calculations, and is not recommended.
I’m sure it’s based on experience or some “fudge factor”. Efficiency has a real definition: the average output of the lowest 25% of locations divided by the average of all locations. Using that figure directly, I think, would tend to overwater the rest of the lawn. So they came up with this figure, which results in a Scheduling Factor to be multiplied by the calculated times. Scheduling Factor is a universally used (but IMHO misnamed) factor, so I image the 1 / (0.4 + 0.6*Eff) is too.
In my heavy clay yard, I would not expect the moisture at 8", or even the 6" setting of my Root Depth, to ever change. It should stay damp down there, with only the ground closer to the surface drying out. It doesn’t do so evenly. The Soil Moisture % and Field Capacity system, which Rachio explains in great detail using several analogies, explains the basic operation of the moisture with the Flex Daily system. Even it is somewhat simplified, but seems to work very well, and is generally accepted in the industry.