Wired Everydrop flowmeter reading and app readings don’t match

post by Fl-user on Mar 1, 2024

My neighbor and I installed the Rachio 3 back early December. We have since both installed the wired flowmeter. Both of our systems ran last night. My neighbor read the current value on the meter yesterday to compare with the app. I didn’t read mine last night but I did today so I can check with my app next run.

Anyway, the values do not match. Rachio has 1717 total and the flowmeter shows 1785. Granted this is only a 3.93% difference (67.5 gallons) but if Rachio is reading data from the meter, shouldn’t they match? And 67.5 gallons is significant.

As a side note, if you look at the calibrated flow for a zone and multiply that by the run time, you get a 3rd value that is even higher than the app or flowmeter.

As an example

GPM 11.9

Runtime 33 minutes

11.9 x 33 = 392.7

App said 324

When you do this for all zones, total calculated gallons is 2025.4. Very different from the 1717 and 1785 above.

post by JBTexas on Mar 2, 2024

There are more than several reasons that the volume shown on the face of the flowmeter vs. the volume shown as delivered by Rachio vs. the volume actually applied to your property may vary:

• Controller settings for pressurization and settle times when starting and stopping runs. Whether pipes from the meter to the valve or from the valve to the sprinkler contain air or water and how long (and how many gallons) it takes to fill or empty the pipes.
• Similarly, the length of those pipes. I have 8 zones and distances of from 20 to 100 feet, downhill, between the meter and the zone valves. It takes over 40 gallons of water to fill those pipes.
• Whether you’re soaking while watering, particularly for zones on a slope, where the valve-to-sprinkler pipe is unpressurized and empties during soaking and must be refilled.
• How accurately you’ve calibrated flow for each zone, including variations in pressurization at the time of day you calibrate vs. the time of day you water.
• How accurately you’ve determined the zone parameters that will be used by Rachio to determine, along with the GPM reported by the flow meter, the water applied. One of the most important is the zone’s Area, which you should know accurately to calculate Precipitation Rate.

It appears Rachio doesn’t require “real-time” flow meter input for Usage determination. The Baseline Flow calculated during calibration is used for the high/low flow alarm triggers and flow monitoring or shut off. The Advanced Nozzle Inches Per Hour setting appears to be used for backward-estimating usage when a contemporaneous determination of usage in a zone can’t be obtained from the flow meter.

post by Fl-user on Mar 2, 2024

Thanks for the explanation. Your second bullet point doesn’t seem right. Wouldn’t the meter see the over 40 gallons needed to fill the pipes? And likewise with bullet 3 - soaking time and having to refill the pipe. All this water still goes through the flowmeter. Are you saying that the Rachio app doesn’t “see” this water? If so, any idea as to why?

We have Hunter MP heads where the PR is 0.4. This is the value I entered into the app. Looking at the data I compiled I can’t make sense of it either.

Zone 3

GPM 10.4

Run Time 41

Sq ft 2229

Available water 0.12

Root Depth 4

Allowed Depletion (%) 50

Efficiency (%) 80

Crop Coefficient (%) 65

Inches per Hour 0.4

App Gallons 386

Calculated gpm/sq ft 0.1731

Zone 4

GPM 6.5

Run Time 41

Sq ft 949

Available water 0.12

Root Depth 4

Allowed Depletion (%) 50

Efficiency (%) 80

Crop Coefficient (%) 65

Inches per Hour 0.4

App Gallons 277

Calculated gpm/sq ft 0.2392

Why are these different gpm/sq ft? Shouldn’t they be the same? And regarding your comments about PR, are you suggesting that we use app gallons to get a different PR than the Hunter specs?

post by JBTexas on Mar 3, 2024

All good questions, and you’re right about bullet 3 shouldn’t be related to the measurement of the water through the flow meter. I was trying to make 2 points at once, unfortunately, and soaking and refilling pipes, pressurization and settling are related to measures of Usage vs. real water applied to the zone.

I have some data on the EveryDrop 1004-EX that suggests that EveryDrop’s accuracy vs. the curbside dedicated commercial water meter at my home is about ±2% from run to run. Over long periods of time, Rachio is very accurate at reporting metered usage.

We plugged your data into our own calibration spreadsheet and got slightly different results:

There’s no such calculation as gallons per minute per sq. ft. The proper units of measure are inches of water per unit of time and the formula for that is:
Precipitation Rate (in/hr) = 96.25 x flow (gpm) / area (sq/ft)

You’re using 0.4 in/hr Hunter heads, which seems to indicate the flow over the entire zone 3 matches what you’d expect under every head, without any overlap. Zone 4 (0.69 in/hr), if it has the same type of heads, seems to put about 50% more water per area on the zone, suggesting there is more sprinkler density in that zone, more overlap.

If the zones are the same type, when you have it tuned, Zone 4, getting more irrigation per square foot, should take less time to water than Zone 3, perhaps enough to be noticeable (occasional skips).

post by Fl-user on Mar 3, 2024

Regarding gallons to sq ft, I was trying to see if the application of water was equivalent per zone. It isn’t.

So I guess you are recommending I change the PR in zone 4 to the 0.69 instead of 0.4? Is that how this should all work? And do this for each zone?

While I had tried Google earth before to do the measurements, it was extremely difficult. I did however find that the appraiser’s office in my area has a website where I found my property appraisal. It told me that the property was 13,506 sq ft. I looked at my house plans and determined the sq ft footprint of the house, lanai & driveway to be 4706 leaving 8800 sq ft for the yard. There was also a map on that webpage that you could click on. It opened a map of the area with property lines and tools to measure length and area. I redid all of my zones. Looking back at my hand sketch on a property drawing, I had made a couple of calculation mistakes. This map was a lot easier to use.

post by JBTexas on Mar 3, 2024

Yes. Enter the properly calculated Precipitation Rate for each zone as its Nozzle Inches Per Hour. Your flow meter will provide its own measure of how much water goes on each zone on each run. The setting value will be used to calculate Usage if the meter doesn’t provide it.

If you have a tape measure and a helper, you can probably measure all of the 6 zones in 30 minutes.

If you’re growing St. Augustine, your root depth should be the depth you want your plants to go for water, not what they are now. Rachio will use the depth as a reservoir that it will keep from drying out, so the plants can thrive under conditions that require that reservoir depth.

post by Fl-user on Mar 3, 2024

Thank you. I’m using my personal Davis Vantage Pro2 weather station for data.

I had a helper with the manual measurements. I had good data points for the 1/2 way points between zones. I went back to the appraiser’s map and carefully re-drew the zones. I was able to draw in the non-square areas within the zones on the map so the calculations of area should be as best as can be.

post by RPostWVU on Mar 6, 2024

You sound like me when I started this whole endeavor. Wondering why I had like 5% error rates on things, and trying to dial in the settings really precisely with catch cups and 10-15min run times and all that.

post by Fl-user on Mar 6, 2024

Where are you seeing error rates?

I am trying to lower my water usage because with my Hunter controller, it only adjusted for rain using the rain sensor which are known to not be reliable, I know I over watered because my roots were not very deep and the grass just didn’t look healthy.

post by RPostWVU on Mar 6, 2024

I saw the same discrepancy in numbers on the meter vs Rachio reported. Also numbers in catch cups vs Rachio or calculated.

post by JBTexas on Mar 7, 2024

At least be sure to enable this (Controller Settings / Flow Settings):

post by RPostWVU on Mar 8, 2024

Yea, but that’s still only monitoring just after a run. Completely ignoring the other 92%+ of the time that my trunk lines between valve boxes doesn’t leak.