Flex Daily problems

[matt8573]

Hi, as mentioned in another thread. I think there is something wrong with Flex Daily moisture levels. I have 3 zones on two different controllers that have been having similar problems for several weeks. Perhaps this is related to an update or me tinkering with something, but the watering schedule seems to be much too infrequent and modifying the advanced settings doesn’t really increase the frequency.

The following examples are for a zone that I haven’t done a quick run on lately. I have drip emitters between 2-4gph, mostly one per plant. These are a lot of palm trees, tropical perennials. I decreased the root depth to 6” (from 24”) this morning and increased the crop coefficient to 100% (from 75%) with virtually no change in the watering schedule. I’ve also tried changing the zone type to perennials, annuals or shrubs and it seems to make the problem worse. Any ideas? Thanks very much!

[rraisley]

Your Advanced variables look mostly okay (I’m assuming Sandy Loam soil). I wouldn’t increase your Crop Coefficient to 100%, but just leave it at at 75%.

Drip systems are a whole 'nother animal than normal spray heads (which aren’t that easy anyhow!). I honestly don’t know how Rachio calculates times with them (or CAN for that matter). There are so many other variables they have no knowledge of (how many emitters per plant, what size emitters, are plants jammed together, all irrigated, or spread out with dry ground sucking up the moisture, etc.). And while I have my own theories and methods, I’m probably not the best person to advise you on that. The only real unknown variable is the Nozzle Inches per Hour, but with Rachio’s Drip values going from 0.5"/hr to 2"/hr, and IMHO real systems varying more than that, it’s hard to nail down. But rest assured that is the ONE variable you need to try to get right.

If you have areas with grass, or even shrub or other type of crops but are watering the entire area (not using Drip systems), it becomes a lot easier, and I can help more with that. Even then, getting the Nozzle Inches per Hour is very important, yet most will just use the default values.

Enough about that, because I also SEE SOMETHING WRONG: Your digital moisture charts have a problem for YESTERDAY. The moisture level for each day (inches) is simply the previous day minus the Crop Evapotranspiration + Any Rain + Any Irrigation. For 5/9 the value is 0.88". 5/10 had no rain or irrigation, so subtract 5/10’s CE of 0.15" and it should be 0.73". But it’s NOT! It’s 0.24". I have no idea where that could have come from. Even Emptying a zone would take it to zero, not 0.24. So that math doesn’t work that day, but does every other day. Did anything funny happen yesterday? I’m guessing some Advanced or other settings were changed, and from my experience, Rachio can get confused when that happens (or I’m confused about what Rachio is doing, not sure which).

Anyhow, the chart shows the system will water 0.22" tomorrow (a correct amount, BTW, based on your Available Water, Soil Depth and Allowed Depletion), which it needs to, based on the new moisture levels. From what I see, it will probably water most days, skipping only 1 or 2 in a week. That’s not great, but your soil won’t hold much more water, so that makes it difficult. My Clay soil holds almost 3x what your soil does, so I can water much less often.

How about posting next week’s moisture graph and table?

[tmcgahey]

This is the absolute best tool for calculating emitter PR that was done by one of the OG’s @azdavidr. He has it dialed in so that you can correctly set your emitter PR based on the GPH, number of emitters, etc.

Drip Emitter Calculator for Precipitation Rate & Area

I put together a calculator for precipitation rate (PR) and area of emitter systems that do not have continuos, evenly spaced emitters. The calculator is complete, and includes the link to the Web Soil Survey instructions as well. The calculator is easy to use, but please read the notes above the calculator to be sure you give it the right data. The information below the calculator is just a description of the equations involved, so ignore that part of you don’t care for the details. Please …

[matt8573]

@rraisley

Enough about that, because I also SEE SOMETHING WRONG: Your digital moisture charts have a problem for YESTERDAY. The moisture level for each day (inches) is simply the previous day minus the Crop Evapotranspiration + Any Rain + Any Irrigation. For 5/9 the value is 0.88". 5/10 had no rain or irrigation, so subtract 5/10’s CE of 0.15" and it should be 0.73". But it’s NOT! It’s 0.24". I have no idea where that could have come from. Even Emptying a zone would take it to zero, not 0.24. So that math doesn’t work that day, but does every other day. Did anything funny happen yesterday? I’m guessing some Advanced or other settings were changed, and from my experience, Rachio can get confused when that happens (or I’m confused about what Rachio is doing, not sure which).

I think this is it. I’ve been fiddling with my advanced settings and in the past I was used to that not messing with the moisture graph and sort of just working going forward. That way I could see what a change would look like to a normal schedule right away without worrying about past settings. I suppose I could try the empty under the moisture graph?

It looks like my moisture graph and table only goes through the 13th unless I’m missing a way to look further in the future. Once we’re done testing this, I’m going to mess with the emitter PR. It looks like I’d be looking more typically at a setting of .5 inch/hour with my unevenly spaced 2-4 gph emitters. Thanks for your help!

[rraisley]

@matt8573

I suppose I could try the empty under the moisture graph?

If the zone is dry, don’t hesitate to do that. But don’t expect everything to clear up on the moisture graph; I’ve seen Filling and Emptying cause problems too. Basically, I don’t think Rachio likes “change”, but once set, it works great.

It looks like my moisture graph and table only goes through the 13th unless I’m missing a way to look further in the future.

On the PC, there is a small arrow to either side of the Graph portion. On mine, I can go back from 4/30 to 5/25.

On an Andoid phone, where you only see the Graph OR the Table (with MORE), the arrows are only beside the Graph, not the Table.

[matt8573]

Ah, didn’t think of that.

[rraisley]

@matt8573

Ah, didn’t think of that.

This graph shows what I expected. Your sandy soil requires watering almost every day to keep the moisture level reasonable. To be honest, it will get tougher as the summer gets hotter, and you may have to increase the Root depth, Available Water or Allowed Depletion in order to apply more water just to keep up. As long as that does not cause runoff due to excessive watering, that’s okay.

Since you’re kind of borderline here, I would recommend, if you could, calculating a more accurate Nozzle Inches per Hour value. A relatively easy way to do that is to check your water meter reading, run the zone for say 10 minutes, then read the meter again, to calculate the gallons used. Then estimate the square feet that is being watered in the zone (easy if small and rectangular, can be tricky - we can help if you have a drawing or satellite view of the house). From those two figures:

Nozzle Inches per Hour = Gallons of Water Used / Minutes Water Ran / Square Feet of Zone x 96.25. Again, we can help with that if you like.

[matt8573]

Just to give an update, I feel like I’ve dialed things in better now, decreasing the root depth (I went with annuals, even though they aren’t), and decreasing the nozzle inches per hour. I’ll keep an eye on it. Thanks for everyone’s help.

[azdavidr]

Appreciate the shout-out @tmcgahey. I still remember sitting down with a pencil and paper to figure out the stupid equations. I’m glad it’s still relevant!

[tmcgahey]

Glad to see you back here @azdavidr !

[azdavidr]

Thanks. I feel bad about not being around, but there’s that whole time thing that seems to have gotten away from me. I thought I’d have more of it when the kids left for college but somehow I have less. Go figure.

[Linn]

@azdavidr, just wait until you retire! You’ll have even LESS time!!!