Evapotranspiration forecasts

What makes crop evapotranspiration predict (forecast) so high, because then we see about half the amount once the day passes. This is causing more and too frequent waterings.

I have the same problem. It’s not as bad of a problem if your plants get a deeper and less frequent watering.

What time do you start your 1st zone? Don’t start your 1st zone in the schedule the affects it the most until 1am. It will give you one less day of the issue, as the forecasts and past weather is updated an hour before watering.

I believe this is also a reason Rachio has a 110% soil moisture cap instead of 100%.

I have the schedule start at 4am.

What’s the max value for the soil moisture cap? I’ve seen .49 is there a way to make that higher?

It does it automatically for the given setting and advanced setting you put in.

It ran my usual 9pm-11:59pm 0.55” watering even though it actually has 0.04” left and that extra when the ET recalculated. The added moisture was carried over to the next day, hence 108%

Can you send a screenshot of the zone settings, and the advanced settings so that I can compare?

Each setting and advanced zone setting is dependent on the plant species and local environment, emitters etc.


How long do your zones run for?


24 minutes for the zone I showed. I have several zones for the lawn as seen below.

@Gerardv514 thanks for describing this scenario and providing the moisture charts. When you say “tweaking the zones”, what specifically did you adjust that caused their moisture values (and by extension, Flex Daily schedules) to diverge?

I will look into this and get back to you.

@drew_thayer At first it was the allowed depletion I bumped it up to 60, checked the durations and values just to see how it affects the zone then brought it back.

Prior to me factory resetting I was seeing this problem when I adjusted soil type, awc values, the efficiency and even nozzle inches. I would occasionally find that id make a change, let’s say efficiency to 80% saved and then revert back to 70% when I would go back into it the value wouldn’t save and would revert back to 80 or some other whole number with now decimal values after it. While doing this, I would notice the water optimization then got whacky by saying I’m watering too much for my region even the the graph was within the optimized limits.

I was able to tell the settings were off based on the zone duration. All of the zones are set the same except for sun exposure, which only affects the evapotranspiration values and not duration, same for slopes. I had already set those values to all the same exposure and no slope and was still seeing those issues.

What drives the irrigation value in the soil moisture chart? For instance I have a zone that shows .36, which during one run is 26 mins. I know for a fact that in 26 mins we drop about .5” of water. My nozzle inches per hour is 1.15, which was derived from .5/26minutes to get the per minute rate x60mins.

I switched the soil back to sandy loam, from clay. Clay was showing .47 for irrigation in soil moisture chart, nozzle inches was at 1.2

Apparently, this is due to having water hammer on. Just read this discussion which talks about this: