I'm new, please help me understand a few things. Rain sensor, adjustments, etc

Hi everyone. I just purchased and installed a Iro and an external rain sensor on August 1st (2015)

So far, I’m liking the Iro, but I often feel like all of the settings and things are a bit over my head.

Can you help me with any of the following:

1: Rain sensor: I bought one. I installed it, tested it. It shows up in the device history when it activates and deactivates. I’m using flex schedules and I can’t tell if the rain sensor is affecting them at all. Does it play a part in calculating the MAD principals moisture balance at all? (like if I had rain at my house but my nearest weather station did not detect any) Or is its only function to halt a scheduled watering time if the sensor is activated at the time the zone is supposed to water?

2: Rain sensor settings: My sensor allows me to set the threshold of rainfall for activation. Any suggestions on what setting I should use? I left it on the default. Also, this is just a suggestion to the Rachio people, but it would be neat if we could notify the software what our rain sensor threshold is so that the Iro could understand that our location got a minimum of that much water. (Iro would then use the larger of the official weather station measurement and our rain sensor as the official precipitation total)

3: I feel like the Iro might be watering more than my lawn needs. What is the best way to fine tune/test that? Slowly increase the allowed depletion setting until my lawn starts to brown and then dial it back? some other method?

4: It rained a bunch one day and I can’t tell if the flex schedules changed as a result. Is there a way to see what the impact is of local weather?

5: Water Use shows thousands of gallons used and zero gallons saved. What types of events would trigger gallons being “saved”

6: Is there anything else you wish you knew when you first started using the Iro?

Thanks in advance for any support or advice. :smile:


Thanks for reaching out to us. Welcome to the Rachio community!

I will do my best to answer your questions:

So the rain sensor overrides the common wire on the Iro. So basically whenever the rain sensor is activated it will shutdown our system until it dries out. So it has no affect on the moisture balance.

So this is up to you. It will really just depend on how much rain you want to have it trigger on. There is not really a generic setting that we recommend.

You could use this approach. You could also use the raindrop icon to increase or decrease the durations in your Flex schedule. Couple screenshots are provided below:

Sure. I would suggest looking at the moisture level graph in the web interface. This will basically show you exactly what we have done and plan on doing based on the current moisture balance and the predicted temperatures/precipitation.

Gallons saved are going to be recorded based on our weather intelligence feature. So if you are using Flex only then you will not see this. We are working on figuring out a method for this but don’t have anything set in stone yet.

I will let out amazing community comment on this one! I’m sure there is some good suggestions out there.

If you have anymore questions don’t hesitate to let us know.


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just this morning i received a push notification to my phone that said “when i drip you drip we drip was skipped due to external rain sensor”. so this is a case where we got a good deal of local rain that was not registered by the weather station im using but the schedule was skipped due to the rain sensor. now, i wait for rachio to catch up and the zone schedlue should be removed for my flexies.

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Best zone name ever?


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hahaha, maybe? it is actually my flexie name for my drip zones, it is from a horrible rap song back in the day, i put my hand up on yo hip, when i dip, you dip we dip.

dj. flex master mow is the schedule name for my turf zones.

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Idk @plainsane It is a pretty incredible song if you ask me! :smile:

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Thanks for the replies. I’m the kind of guy that likes to know how everything works and likes to tinker with stuff. I have to admit though, the immense set of options available for the Iro is intimidating.
My main reasoning for buying the Iro was because I liked the idea of flex schedules that just take care of things without me having to think about it. But getting that dialed in seems to be very difficult.

So, a few more questions please:

1: What is the Efficiency setting on the zones and how does changing it affect the outcome of your schedules? (I assume it may have to do with how efficiently my soil absorbs and holds water? but I have no idea)

2: Changing “Allowed depletion levels” vs changing the “duration droplets” on the flex schedule section.

  • Allowed depletion levels: increasing it allows the soil to become more dry before watering is triggered.
  • Duration: Increases or decreases the watering time during cycles.
    Is that right?
    Seems like you would then only change “duration” if you see runoff or the soil doesn’t seem saturated enough after a cycle.
    So, is it then better to try to tinker with “allowed depletion levels” in order to find the right balance of lawn health vs water conservation? What is the best method for doing this? Its just intimidating.

3: I’m so spoiled with the nest thermostat. Its great at showing me usage history by day, if weather caused increased usage, and even monthly summaries that I can compare. Is there anything like that with the Iro?

I’m hoping to be able to show my wife that we have saved water/money with this thing, but it seems like if you have the wrong settings in there, you could actually end up unknowingly using more water until you get it all dialed in.

We’ve tried to make this easy, but are always looking for ways to make the process better. Unfortunately there is a lot of complexity. We are looking at ways to abstract more of this away.

This is correlated to water loss.

To truly measure you can do a catch cup test (they call the value distribution uniformity) or just use our defaults which will work.

Quick article on efficiency:

The higher the efficiency, the lower the duration to fill your zone using flex schedules.


If you want to modify watering frequency you can adjust allowed depletion. If your frequency seems OK, I would not touch it.


If you want to modify duration, you can use the water drop or pick a different nozzle type.

In the near future I want to allow modifying frequency with something similar to the water drop. Easy for us to do, just need some time.

Yes, or grass is browning a bit. Back off duration if super lush, or mushrooms.

If frequency is OK, I would leave this alone unless it is watering every day or even every other day and just focus on duration. The ultimate goal is to have longer periods between waterings.

So why is allowed depletion so important? You have heard me echo the plea from horticulturist to water deep and less frequent. It is true, plants are healthier and more stress tolerant when watered deeper and less often. Roots need air; when we water too often, roots struggle to get air so roots stay close to the surface. The concept of deep, less frequent watering is tied directly to Allowed Depletion. As water evaporates from the soil, moisture is “Depleted” from the soil. Irrigation should replace depleted soil moisture once the soil has dried out to an allowed level.


We have monthly reports in the app, but have not correlated this to weather yet.

I think once it is dialed in everything works great. Yes there are a lot of levers, but hopefully you don’t have to tweak too much. We are working on abstracting this more. Starting with one or two zones might be easier, than apply those settings throughout the rest of your system.

Hope this helps


The soil database that you have posted in a topic somewhere around here which shows the soil types would be a nice integration. Much easier said that done but seems to be the hardest question for new users to answer? if you automate access through that api and it requires a license/api fee, this seems like the most appropriate use a micro transaction. You are not nickeling and dimming the customer, if you want to make a manual choice, no problem, else for $1 we will query a server and provide you a choice list of 3 types.

Take that idea further with the Google maps api that lets you take rough area measurement via the sat image. Again I’m sure Google wants some $ since they can’t stuff an ad down your throat.

Agree with all of these, initiatives for this year and next.


Thanks for all of the prompt replies and help and patience.

So would it be a good idea to buy one of these moisture sensors and then try to use it to probe my lawn to get things dialed in?

What would the process look like for that?

-Put the sensor in the soil to the root depth of my grass
-Compare that to the moisture level indicated in the Iro software

  • If the soil is more wet than what the software says, increase the “allowed depletion levels” if its more dry, decrease the “ADL”
  • Also factor in any physical signs like you mentioned above (lush/mushrooms or browning)

Personally I’d hold off on adding that level of manual sophistication/complexity for now.

Maybe see how the system works first before using soil moisture tools.

If the system gets close enough with fine tuning you might not need to add those types of sensors.

Ultimately we will probably end up incorporating soil moisture sensors tightly integrated with the Iro, but there are still issues with price and utility.