See this thread:
In that thread, I posted this, back in 2020:
I use a 16 zone Gen 2 (with 13 zones being used) and have for a few years.
I live in Palm Beach County, Florida. We water here year round. I get reclaimed water, so never any water use restrictions, and the water is very cheap.
I tried Flex Daily and Flex Monthly. I really tried to make the scheduling systems work, and spent a lot of time to try and understand how they work, asked a lot of questions on this Community, but in the end found it too complicated, and I finally reached the limit of the amount of time I was willing to dedicate to this.
It has been over a year since I gave up, but I remember playing with the settings and watching the zones percentages of saturation, hoping it would water my grass while I watched it turn brown.
I have a Davis Vantage Due weather station, connected to PWS Weather (PWS_BOCA33432) with a Meteobridge, which is a considerable investment. So my Rachio has the advantage of knowing exactly the amount of rain I am getting, the temperature, wind speed, the humidity, etc., but I still could not figure out how to configure it to keep my grass green.
Unless you live somewhere where there is no rain, I think having your own weather station where you get the exact weather information probably goes at least half way to the goal of saving water and getting your yard the correct amount of water, even if you are on Fixed schedules.
So for now, my Rachio knows if it rained, the wind speed, and somehow it figures out if it is going to rain in the next 24 hours, usually correctly, all from my Davis weather station, and it usually does not run when not needed.
The other thing I have done is to install drip irrigation on everything that can be watered by a drip line, and kept my spray heads in good shape.
I notice that a lot of people that have replied to this post say they are engineers or worked in tech jobs for Sony or Silicon Valley, and even these engineers and technical folks think the system is too complicated. I agree if Rachio wants to be a successful mass market device, it needs to be able to attract people that are not technical and right now is way too complicated for the average consumer. Most people do not want to have to spend the time it would take to understand how to make this work. In my case, I gave it a lot of time, but in the end just reverted to an irrigation timer, but with the benefit of it knowing how much water I get at my exact location.
And I too offer this in the spirit of friendly advice. I want Rachio to be successful.
Thanks for considering my comments.
This resulted in a comment:
Just FYI, your Rachio definitely can/does use the rainfall from your PWS, but none of the other information (from your PWS). That information it gets from larger stations, or multiple stations, but not yours.
And my response:
Your explanation does not agree with what I was previously told when I specifically asked if the forecast came from my PWS or the NWS, or other weather sources.
I was told that Rachio (at least Gen 2) only uses the info from my PWS and “years of weather history that Rachio has on its servers”.
I don’t remember who told that.
This got me looking back at some of my posts. I asked a lot of complicated questions, and one of them was this from June 2018:
If a zone starts a day with current moisture balance of zero, as long as the forecasted rainfall for that day is greater than the evapotranspiration that is expected for that day, that zone will not water. In the case of my zone 5, on June 22, that zone was to end the day with current moisture balance of 0.26. But if it did not rain on June 22, it would end the day again at zero.
So, in that event it would start June 23 at zero (like it did on June 21 and June 22), with rainfall forecast of 0.24 inch and evapotranspiration forecast of 0.13, and it would not water that day either.
Assuming it did not rain on June 23, and if it did not rain on June 24 and June 25, each day would start at zero, but since rainfall for those days is forecast to be higher than evapotranspiration it would never water on those days either.
So, assuming the forecast does not change, and the forecast is wrong and it does not rain, is it possible that this zone would never run as long as this is the situation?
The answer to my question from “theflexdude” was:
Yes, it is definitely possible. We do take probability into consideration, but we can only be as accurate as the data from the weather provider.
My response was:
Perhaps occasionally it would be better to overwater rather than risk this happening. If a zone ends each day at zero for several days, perhaps the system should eventually run even if rain is forecast on, say, the third or fourth day this has happened, even if that were to risk an occasional over-water.
Now that I look back, this problem, and similar complications, may be why I gave up on Flex. I do remember that I had a lot of rain forecast, but it would not usually rain. Perhaps this is unique to SE FL.
You can read the entire thread if you want, there are a lot more comments. But after fooling with it for years, I gave up and just use fixed schedules now.
If you are serious, I do recommend that you install your own weather station. There are simpler weather stations than the Davis, which will not directly talk to the various weather web sites (needs something called a meteobridge to do that, which is expensive or complicated to implement) but having the exact rainfall is very helpful, compared with the typical rain sensor that you can buy for the typical irrigation timer.
Hope this has been of some help to you.