Rachio - Baptism by fire and 2 months into it, a few things i've learned

I’ve had my ups and downs with my Rachio. Over the past weeks i’ve learned a bunch and i hope others find it valuable if i share my experiences.

For the record, i’ve had a rachio for several years, but i had it on a tiny backyard and 2 small zones. I moved in the spring to a big property with 25 zones, multiple lawns, hedges, perennials and a 2 zone vegetable garden. It had an old fashioned weekly timer, not a smart watering system.

Once i understood which settings was really important and got them right, the lawn, shrubs and trees are looking well. With a bit of time and mental gymnastics i root-caused (pun intended) the problem i had with my lawn looking unhappy and my water bill being really high is starting to go away.

My water bill was out of control
I got a water bill for $1K and i knew i had to do something. I ordered two Rachios and hooked them up. I also knew i needed to do something with my popup nozzles, they where 20 years old rainbird popups and in poor shape. I initially set things up for flex daily, using the defaults. I did cup catch tests on the lawn to set the nozzle inch/hr. I had something like 5 cups that i moved from zone to zone using averages per zone. Yet my lawn started to look terrible. I increased the watering, but my bill went up even more without my lawn looking much better. To be honest, i didn’t love Rachio at that moment…

I’m getting happier with my Rachio
I spent the last month really trying to understand it, and understand the landscape it supports. Once i took the time to do that, it started to deliver…

I still think it is needlessly complex, especially in the language and UI, but I’ve invested enough time and mental capacity to learn how it actually operates, the language of irrigation and agriculture (crop coefficients anyone?) and the math Rachio is using and how the physical world maps to that math.

Once i understood which settings was really important and got them right, the lawn, shrubs and trees are looking well. With a bit of time (and a bit of analysis) i root-caused(!) the problem i had with my lawn looking unhappy and my water bill being really high.

I’m writing this to lay out my journey for others to benefit. This is roughly in order of importance for making Rachio work for me (at least in my experience). I use flex daily and i have 2 Rachio Gen3 16 zone controllers.

1 Get your root depth right, or at least get close.
You must know your actual root depth, especially if they are shallow. Pull some patches of grass out of your lawn. Check the root depth. Its really, really important to get that right. Mine was significantly less than the default provided by Rachio. As in 2 inches root depth vs the 8 inches that is the default for cool season grasses in the big trouble spots. That and supremely hot weather made no/little water get to the roots and my lawn was drying out. For deep roots it doesn’t matter as much but for shallow roots things get brown fast if you have not set this right.

Another point worth highlighting is that root depths change. Root depth for tomatoes are different in the beginning of the plants life vs. the end of the plants life. You may need to change the root depth for crop that has that kind of growing season. I am now doing mid-season root depth changes for my veggie garden.

Over time i plan to train my lawns by slowly adjusting root depth in rachio, training the roots to go deeper. But that is an over time effort, over months not done in one day. Think like changing root depths by an inch once every six weeks during the most intense growing season. But for that to be successful you need to make sure you have the soil to support the root depth you want (a soil probe or a decent shovel is a good thing).

2 Make sure your soil is healthy
My soil was supremely compacted in the lawn that was hurting the most. In fact i think the water capacity (as in infiltration rates) was less than half of what rachio calculated. I had runoff and pooling of water on the surface which i didn’t particularly pay attention to, which evaporated during the hot days we’ve had in California. I did not have the water uptake that rachio’s model predicted that i would have.

Once i understood the problem, I addressed this in the short term with a liquid surfactant (liquid soil softener) which worked really, really well (it surprised me how well it worked). Custom lawn solutions sell a liquid soil loosener on amazon which i used. Worked really well. I plan to use a mechanical aerator as well as a thin layer of compost later in the fall when i reseed to further help the lawn. But dang, getting my infiltration rates to match the rachio model was key. Much, much less runoff!

On a side note, I figured out that my gardener was doing frequent shallow watering to compensate for the soil compaction which was the key reason why my water bill was skyrocketing prior to Rachio. I don’t think he realized he was in reality not helping the lawn, he was making things worse.

3 Get your nozzle output right
Rachio determines how long a valve is turned on proportionally to how much water it thinks your nozzles output. If you get that wrong you’re not going to get good results.

The choices you have are:

  • Catch cup test.
  • Use the output of the sprinklers from the manufacturers spec sheet and hope they match reality.
  • Use a flow meter to measure gallons of water used in the zone, measure the exact size of the zone, and use that to calculate the inches of water provided per hour in a zone.

Whatever you do, don’t use the defaults -get this right!

I bought Flume Water’s realtime water reader (which is absolutely great), hooked it up to my water companies meter and turned on a zone for about 10 minutes. About 5 minutes in i check the per minute gallons consumed according to Flume. I now know the exact amount of water output into a zone per hour.
I then took very precise measurements of the zone using a highly accurate laser measuring device. My coverage in each zone is uniform (see the nozzle section), which lets me take these two measurements and calculate the inches/hr of water for each zone. This requires you to have somewhat uniform coverage in each zone so make sure you do. And if you don’t have uniform coverage the catch cup tests and judgement calls on what is right will be what you have to do.

Some people will worry that a laser meter won’t work well with trees and hedges, my opinion is that if you have large enough distances that you’re measuring errors while big in inches aren’t big in percentages. You’ll get the water about right as long as you can keep your precision to inches at least. Use a helper and a very good reflective pad if you go the laser route. Take your samples at dusk or dawn, sunlight tends to confuse all but the best lasers and its hard to chase the red dot and put it on the target to get a good distance read. A laser for 200-300ft readings can be had under $50 at amazon. It will calculate the square footage for you (but i recommend bringing a notebook and taking good notes. If you don’t have square areas, carve up the area to several smaller areas and add them together, just like you learning in trigonometry in high school :grinning:

To be honest, i verified my math by also doing catch cup tests in 4 zones. Maybe a bit overkill, but it is so easy to do that it was worth it to me.

What i love with the technique of knowing zone sizes and water output per zone is that it makes it easy to measure drip lines. Catch cup tests are impossible on drip lines, but piece of cake with the this approach. Flume has about 2% error rate in tests (and i tested it by running water in exactly 6 gallons/minute flow in a bucket which flume read correctly as 6 gallons/minute). I also found a 0.1 gallon/minute leak in my ice maker so the flume paid for itself.

4 Fix your nozzles
If you don’t have uniform coverage you’ll have areas in your lawn with too little or too much. Worst case you’ll have a mushroom plantation and brown spots at once (yeah i had that when i used the defaults).

Make your coverage uniform so that you get about the same amount of water everywhere you need it. I changed to MP Rotators which has worked really well for me. Easy change, and easy to retrofit. Not that expensive either, good Rotators from several suppliers can be bought online. I use combinations of different styles of Rotators but i match their precipitation rates to ensure uniform coverage in a zone. With rachio the zone can run for different lengths of time, and the rachio will do the math for you -but you need to make sure that you have uniformity within each zone -not across zones.

I changed old drip lines to rainbird XFS drip lines at 0.6 gallons/h per emitter and 12" spacing (a bit longer run times but i think it works better and i asked professional landscape builders who steered me towards them). Totally worth it, and drip lines have been great for all my hedges and perennials. I typically lay out three lines in a grid connected top and bottom with each other for uniform pressure.

What about coefficients and irrigation efficiency?
These things matter, but less than the above. The defaults won’t screw you over. Until you get the stuff above right, don’t worry about these for now. But once you get the above right, then get at least the crop coefficient right.

Any crop that has any commercial value has a crop coefficient (or at least that is my experience). I looked up the coefficient using my local agriculture university website (using google search). For me in my area UC Davis had much of what i was looking for. It took no time to google, and on this forum you can find the most common crops described. Note that the UC often has a different coefficient for open field vs green house. You want open field. Many crops have different coefficient when flowering, fruiting and dormant. Pick a sensible average.

If anything, i wish the forum had a database of common crops and their coefficients that users could share with each other for mutual benefit. If anyone wants them for figs and for pomegranate, ping me as they where hard to find…

Efficiency doesn’t really change things that much. Its worth adjusting between nozzle and drip, but for the most part it wont make any dramatic changes to anything. i use 80% for MP Rotators, 90% for drip lines and 60% for two older sprinkler heads. I ran the math, and this just doesn’t change the output of water by a huge amount.

Don’t override the schedule times once you create it
There is the popup when you create a schedule where you can change the times per zone. Don’t do it! Let the Rachio run its schedule and just leave it alone. If you need to put some more water into the soil prior to creating the schedule using a quick run zone. But don’t do override it, i think its better to run the schedule based on Rachios math than a human intuition and if you’ve done the things i outlined above the math will get it right for you!

Thats it!
I did this and my yard is happy. I have not yet gotten my new water bill, but Flume is tracking my water and is predicting that it should be half of last months bill. Maybe half of that saving is cooler weather and maybe half is more efficient irrigation.

I hope this helps someone. These are my experiences and i don’t want to claim to be an expert, but i’ve spent time to get a very problematic lawn to work well with Rachio.


Very nice writeup. I pretty much agree with everything, so it must be right. :wink:

To me, that is the hardest thing to get accurately. As I’ve written up elsewhere, I have what is probably a low-builder-grade irrigation installation, with 6 zones including a soaker/drip zone. While 2 of my zones overlap, the other 3 are well-defined, and drawn by me accurately using CAD software, so I /really/ know my square feet of those 3 zones. And my digital water meter reports in 0.1 gallon increments.

For my Rotor Head spray heads, Rachio says my Nozzle Inches per Hour should be 1.0. By measurement using actual area and water flow, I get 0.44" per hour. Using 12 Orbit Catch Cups, I got 0.39" per hour. My Catch Cup totals come out to only 88% to 58% of what the area/gpm values do! The only explanation there is that, with my low Efficiencies of 21% to 53%, catch cup location is Critical!

So, I have a screwed up system, but so do many people. I don’t know how we’ll ever get an easy to determine Nozzle Inches per Hour measurement! IMHO, Area & GPM is the best, but a lot of people can’t measure the area easily, due to shape, tree coverage, etc. It’s really a problem, I think.

Awesome writeup. Thanks for taking the time to do it. I will refer back to this writeup when I fine tune my configuration.

One of the big reasons why i switched my nozzles to mp rotators was the problem you outlined. Uniformity of coverage is important for water savings. I knew i did not want to use averages based on zone overlaps or poorly performing nozzles. The adjustable mp rotators worked well for me at the expense of much longer run times.

I should also really have moved the location of the nozzles, they aren’t placed that great. But i couldn’t justify that expense.

But yes, i think its challenging to get Rachio rigth when you have a deviation vs. the mean that is upwards of 40%!

One more point that is worth repeating.

lets say you have a clay soil. Iniltration/water carrying capacity is 0.15 in/in (you can see that in the app gui).

If you want to put down water to 3 inches depth, then you need to put on 0.15 * 3 = 0.45" of water on the surface. If we wanted a lake then we put on 3" of water -but then you won’t have any soil. The amount of water we can put on is only the amount that can be absorbed by the soil.

I think the point of inches of soil absorption vs inches of output often is forgotten -its worth remembering.

To make that visually make sense, I think the moisture graph UI should be rendered with a root to the bottom of the graph (representing 100%), a line showing the allowable depletion, and a gradient overlay showing water level in the soil. I think that would help visualize what actually is going on currently and historically. I would overlay in the graph a sprinkler on top (shape it like a watercan) that shows watering events.

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I have some parts of my lawn pretty compacted due to the house being “newly built” (2 years go). There are some paths that are compacted due to the heavy machinery bought in to do patio, driveway, grading etc. I have not aerate yet but am going to. I was going to buy some liquid aeration but since I’m going to do mechanical aeration soon, I didn’t want to get the liquid aeration.

@jtuber, I get my lawn mechanically aerated (and overseeded) every year in the fall, and have done it since I moved into this house 13 years ago. It has helped a lot and is a good lawn care practice, from what I understand.

I actually think they work well together. I read the science behind liquid aeriation and while it is not a cure for everything i don’t think it hurts either.

Yup, aeration, top dressing and seeding should be a part of lawn care. However, you should not do it or need to do it every year.

As for liquid aeration, I don’t doubt its benefit but since I’m going to do mechanical aeration, I didn’t think it was needed. Not hurt but unnecessary for the time being. That’s all.

I’ve tried Liquid Aeriation myself, just once so far, using Nature’s Lawn & Garden’s Aerify Plus Soil Conditioner. It’s supposed to reduce thatch as well as aeriate. With Clay, which I have, mechanical aeriation does make holes, but I’m not sure it actually helps the clay in between any. And the plugs lay around and have to be “mowed” to start disappearing. I plan on applying the liquid a couple more times this year.

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@rraisley, from what I read, liquid aeration is temporary and last only a couple of months. It should not be a replacement for mechanical aeration.

Maybe, but I think it’s just the opposite. Mechanical aeration is /absolutely/ temporary. Once the holes fill in, it’s no good any more. Liquid (not the soap suds kind that just keeps water in place) is supposed to break up the particles, especially clay. I think/hope that will be more permanent.

But you’re right, like so many products, we read pros and cons of everything.

The holes will be filled eventually but the soil won’t be as compacted as it was before. Repeatedly “hole-ing” the soil would eventually un-compact the soil since you churn it. Liquid aeration just opens microscopic pores in the soil by chemical but once that chemical is gone, the soil is compacted again. That’s my understand from researching.

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Just go to the nozzle manufacturers website and read the chart for your nozzle. If the top is hard to read take a close photo of the top and then blow up the photo on your phone.

In-line drip tube is easy because its precipitation rate is fixed. Determine who made the drip line and note color of the strips on the tube and look it up on-line.

If you have individual emitters on a blank tube note the colors and brand. It’s best that they all have the same precipitation rate.


After physical aeration, apply a fine organic compost 1-2", not mulch, and some of it will enter the holes and keep the air in the soil. The compost will be good for your turf too.

Yes, I agree. Some of the programming information and charts are NOT intuitive even if you are an irrigation auditor.

@ParB Thank you so much for taking the time to post! I’ve battled a season of fungus and weeds because the controller was not set up properly when installed. I’ve been putting together snippets of information from many sources and your post was extremely helpful to me. Thanks!

Same here, thanks for taking the time to post this! The secret I needed for my lawn was the root depth; I’ve felt that my lawn was being over-watered since I was getting mushrooms sprouting but couldn’t figure out how to throttle it back. Now I know.

I’m glad the post was valuable to you! And Thank you so much for giving me feedback, i find it motivating to share experiences for the benefit of others. @rraisley was hugely beneficial to me, helping me internalize and create a mental model of how the rachio actually works.

My yard looks great. I had my irrigation guy come out and he spontaneously said “you really got the rachio dialled in, your garden looks great”. I now use daily flex for all zones including my vegetable garden. It works great! Root depth, water output and crop coefficient is key. having a good weather station not too far away helps if you live in a place with big variability in microclimate.

my water bill went down by 30% the first month after i got it dialled in. I expect it to go down another 20% this month based on the water consumption data my flume is providing me with. Given the high costs of water in california it means i will have my investment in rachio and new sprinkler heads paid off by next spring. Not a bad deal, if i can get a couple of years life out of this investment.