Feeling Much Better Now

First thanks to everyone who has responded to my other posts, to the forums for their excellent Search system, and to Rachio for providing a lot of technical information. I think I understand what I need to for now, and have tuned my schedule to where I think it will work for me. During that process, here’s what I’ve found:

I’m using Flex Daily, as it responds best to temperature changes, as well as rain and other conditions. I’m really quite impressed that if I do Test watering (for catch cups), or add a bit of water here or there, that Rachio knows and remembers all that and includes it in the day’s moisture analysis.

I’m in Columbia, South Carolina, and have confirmed that the Available Water per Inch of soil is 0.17, which is what Rachio entered for Clay Loam. I confirmed this based on land survey information online, so that’s good.

Naturally, I selected Warm Season Grass, and here, I think, the program could use some improvement. There is a LOT of variation in warm season grasses, from Centipede (which I have) to Bermuda to St. Augustine, etc. For Warm Season Grass, Rachio gives a 9.84" Root Depth and an 65% Crop Coefficient. But sources indicate that Centipede has 6-8" root depth and an 85% Crop Coefficient. Making those changes in the Advanced screen (I chose 6" root depth to start, and can increase it if I feel it’s not enough) reduced water application per cycle by 40%!

For now, I’m leaving the Efficiency at the default, and have manually changed the Nozzle Inches Per Hour to my manual calculation based on area and water usage. I will change both to “actual” values after I do my Catch Cup testing (delayed because I have some known problems in that area).

I am 100% convinced (okay, 80-90% at this time) that adjusting watering amount should be done with the Root Depth value. Changing it is /directly/ proportional to the maximum water applied per day. Double it, and you’ll use twice the water. Decrease it by 10% and you’ll use 10% less. Now that’s per watering cycle, and there may be some variation in frequency, but it’s less noticeable than soggy grass. I won’t say that adjusting other factors can get you to where you’re going, but I have faith that Rachio knows a lot about watering amount and frequency, and can calculate that part fine. What they don’t know is how deep /my/ root system is, nor how /my/ soil affects it and the water it can hold. Adjusting Root Depth seems to take care of that.

I will interject here that IMHO the WORST adjustment a person can make is changing the watering TIME. That takes away all intelligence of the inherent code, and you’ve turned the system into a manual system. If you KNOW the time is off, change Root Depth or other variables to correct it.

So, I now have a darn soggy yard, from 3 days of over-watering (and Rachio knows it - on the graphs), with my new settings, and I think I’ll be close going into the future. I may need to increase the Root Depth as we go on, but it should be easy to manage. Were Rachio wanting to have a More Dry <> More Wet slider, I think if it simply modified the value of Root Depth used in the calculations (not displayed), that would satisfy most people. Until then, I’m happy to adjust it.


The most basic aspect of a good UI is to understand user intention. Rachio is awesome because of how many inputs and technical factors are considered by the system, but the most import factor is “how much water does this user want to use for this application?” That factor is indirectly represented but should literally be the first thing asked. Some people want a lush green turf lawn irrespective of water use. Otherwise live in an area where water is costly and are okay with some dormancy in their lawn. People have different purposes for when and how they use an irrigation system in the first place and this isn’t as well captured in the UI.

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Thanks for the insight. I was just contemplating how to tweak watering on what appears to be a slightly soggy yard. I had decreased (smaller) root depth earlier and I’ll increase it and see what happens.

But I think that increasing Root Depth will add more water, more often, increasing water application and making your yard more soggy. How much time have you given it with the decreased root depth setting? You’d have to wait at least a day after it watered the next time (after drying out) to tell.

I’ve also discovered that increasing/decreasing the nozzle inches per hour can be a nice tweak. I have part of my grass that is under trees, and the trees really soak up the water. So I decreased the nozzle inches per hour a little bit – that gives it a little more water than the other parts of my yard without changing the frequency that it is watering.

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I agree, that will certainly work. I don’t care for it as much, though, as I intend to spend a bumch of time in this 100 degree temperature getting accurate data for those values, and don’t want to throw them away! :wink:

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I just made the change after I posted and the system is not planning to water tomorrow. To your point I will evaluate it tomorrow to see how things are. The RZD change should add more water but run less frequently per this support article.

I also had this 4” RZD setting since startup (a week or so ago) and had noticed the soggy soil so I was considering what to change next.

From what I can tell, the only 3 factors that determine how much water you get AT ONE TIME is the Available Water in/in, the Root Depth (which you’ve lowered to 4" which is pretty low) and the Allowable Depletion (I think 50% is a good value). Oh, and the Efficiency, to an extent. For a 0.2 Available Water, 4" Root Depth and 50% AD, Rachio will try to apply 0.2 x 4 x 0.50 = 0.4" of water. That’s not all that much. If your lawn /needs/ watered, I doubt 0.4" of water would make it soggy. If it doesn’t need water, then it’s being applied too soon, maybe due to other factors. If your lawn is soggy now, mark the zone as Filled (Zone > Edit > Fill button at bottom). It shouldn’t water again until it gets close to the Allowable Depletion.

Oh, make sure you have Smart Cycle turned on, in case you are applying the water too quickly for your soil to absorb. It will pause to let it soak in, rather than run off.

Look at me, acting like I know what I’m doing, after a week! Please feel free to ignore, or better yet, correct me, if I’m wrong I’m still learning, but a lot of it makes better sense to me now.


You’ve got a ton of great points. Yes 4” is pretty low. I’m guilty of abusing my lawn and am trying to be kinder to it. I do have smart cycle on. I’m in NC and we have Cecil soil, so it definitely needs time to soak. I used our city’s GIS tool/data to look up soil type and slope then I used the web soil survey to get the AWC.

I’ve made the RZD 6” with the hope of deeper watering to encourage root growth along with decreased frequency (MAD 50%) to hopefully not water soggy soil.

That’s a good way to, and it will certainly work. Lowering the nozzle inches value will cause Rachio to increase watering time, trying to get the same amount of water it thinks should be there. But you’ve actually applied more, keeping the lawn wetter and giving more water to the trees. The only thing I don’t like about it is that I intend to calculate, accurately, the nozzle flow, and would prefer to change something I am unsure about, like root depth. But that works too.

I agree with you 100%. Just something I’m trying as the trees take up so much of the water in just this one part of my yard.

I have the same thing: a 3100 sq ft zone, with a 625 sq ft mulched zone with shrubs within it plus a 60’ pine tree and a 25’ really full evergreen as well. What I’m considering trying is tapping into the zone’s irrigation piping, and putting a hose with a valve at the end of it to give substantial water to the large pine tree (and maybe the other tree). I could measure with a bucket the flow from the valve, and adjust it to give the extra water I want to the tree(s), and then I can still use catch cups to determine how much water is actually going to the lawn, and use that setting in Rachio. I think/hope that will work pretty well. I can’t do that kind of thing everywhere I have a tree, but think I can here.