Zone Moisture % Calculation

post by carrera997 on Aug 4, 2021

I recently installed an Ambient Weather WS-2000 weather station with wireless soil moisture sensors.

Which got me watching the zone moisture estimates in Rachio 3 app.

In short, they’re wildly wrong: 0% one day, I set to 100%, then the next day they’re mysteriously all at 110% with no rain or irrigation.

Most of my zones are standard default values, except I’ve learned that grass / flowers prefer 20-40% moisture levels and it’s best to deplete down to 20% before watering heavily again to promote deep root growth, so I’ve set low value to 20% from default 50%.

Meanwhile, the actual soil moisture sensors are reporting consistent 51% values with slight drops each day, as expected.

Anyone else seeing wacky values like this?

post by gaustin on Aug 4, 2021

@carrera997, Rachio soil moisture does not correlate with actual volumetric water content. I have posted about this extensively here: Soil Moisture - Accessories & Sensors / Soil Sensors - Rachio Community

Hope this helps explain it somewhat.

post by tmcgahey on Aug 4, 2021

First off, post some screenshots of the moisture graphs along with the “more detail”.

Second, soil moisture percentages in Rachio, and moisture percentages you are getting from your probes aren’t the same. 0% in Rachio is actually what you have Allowed Depletion (AD) set to.

post by carrera997 on Aug 4, 2021

I think that right there is part of the mystery. Thanks for that. Still not clear how Rachio % would increase from 100% to 110% in one day without precip or irrigation.

post by tmcgahey on Aug 4, 2021

That is where a screenshot of the moisture graphs would be helpful. Were there any zone settings changes made?

post by rraisley on Aug 4, 2021

You said above “I set it to 100% and the next day it was 110%”. The only way you could have “set” the zone to 100% is to press the Fill button, which I think does set the moisture to 110% (that’s what Rachio considers as completely filled).

post by tmcgahey on Aug 6, 2021

Confirmed it only “fills” to 100%. I’m thinking a zone parameter may have been changed causing Rachio to recognize more moisture in the soil.