Zones not running when fully depleted


#1

Can anyone tell me why my this zone has not run yet?

I have two zones like this.

Now, I am sure that rain was forecast for 6/20 and 6/21 (rain is forecast every day for the next two weeks, I am in Boca Raton, FL), but once the day is over, the system updates this screen and replaces the forecast rain with the actual rain fall from the PWS on my property, which is zero for 6/20 and 6/21, and pretty much zero for all the days prior as shown on the graph.

So on 6/20, once the day is finished, it knows that it did not rain that day, and that the current moisture balance is zero, but it did not run this zone. Did it not run because rain was forecast on 6/21? If so, that was a mistake, because it did not rain on 6/21 either.

I see that rain is forecast for 6/22. So it did not run on this zone on 6/22 either. Was that because rain is forecast for 6/22? And, if it does not rain on 6/22, but there is rain forecast for 6/23, will it never water as long as rain is forecast the next day? See next screenshot:

But many other zones I have did not do this. Here is a screenshot of a typical zone that did run, and it ran on 6/20; i.e. it did not wait to run because rain was forecast!

What am I not understanding, or what have I set up wrong?

Thanks!!


#2

I have checked your zone 5 data and here are the values that the system received at 1am each day (1 hour before schedule start):

20th:
previous balance: 0.151
forecasted: 0.015
crop evapotranspiration: 0.163
ending balance: 0.001

21st:
previous balance: 0
forecasted: 0.205
crop evapotranspiration: 0.162
ending balance: 0.043

We always consider the forecast & observed for today and forecast only for the future dates. Since your schedule runs at 2am, we almost always will be computing based on forecasted precipitation, because most times observed for that day will be 0 at 1 hour before start. If we didn’t consider forecasts then we could have the opposite situation when we water, but you get rain later in the day. I hope this explains why zone 5 didn’t water on those 2 days.

I notice that previous moisture balance for zone 5 for 20th is different in the graph now than at the time of check on 20th at 1am. Were any zone characteristics or other settings changed in between then and now?

If you look at the zones that did water, their previous moisture balance is lower than zone 5 and forecasted precipitation wasn’t enough to keep the balance above zero.

Let me know if you have more questions.


#3

Thank you for your response.

First, let me say I did not make any configuration changes in the past week. I am not sure why the numbers you show are different than my screen shot.

If I can put what you said in different words to help me understand, is the following correct:

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?

Thanks, I appreciate your assistance!


#4

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.


#5

Wow, thank you for such a quick response.

It is very helpful to fully understand how this works. I have read everything on the help screens about MAD, including a technical paper on MAD, as well as the help screens regarding the Flex Daily schedules, and definitely missed how this really works.

In my case, my weather provider is my Vantage Vue weather station (with a Meteobridge device to update pwsweather.com), along with the many years of weather history that Rachio uses to determine the forecast, which I would think is not as accurate as the weather service forecast.

In my case, it did indeed rain today, and a lot. My PWS reported 1.13" of rain today, so of course my questions to you were academic in my attempt to understand. So, I will have to keep an eye on the situation (can’t just set it and forget it!), although when I am out of the country from July 26 to August 10, during some of the hottest weather we will have, I can only hope that the hypothetical situation I asked about does not occur.

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. I know that even if that were to happen, my Rachio Gen 2 has used a lot less water than my previous timer based system did.

Again thanks for the quick response, and thanks for the clarity.


#6

I second this!!!