Add Number of Heads on a Zone for Accurate GPM

Yes it does, I’m using one…

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Yes, this could be a solution. But I don’t see it as realistic because of the cost of these devices. Plus, this is a feature usually reserved for high-end central control systems like Toro Sentinel, Rain Bird IQv3.0 or Irritrol Rain Master Eagle Plus. Do you have a flow meter in mind?

We use the RainBird FS series sensors in conjunction with RainBird’s IQ control center. They’re spendy for sure but if your wanting accuracy then look no further and buy their smaller model like the 1" FS100.

I suspect one problem with this method is there may be a point of diminishing returns where someone added one or two too many heads on a zone. At that point even with a regulator the zone may be unable to maintain a steady pressure state due to a lack of water volume being supplied, and all of the heads lose some output volume which brings you right back into having to measure and create custom heads in the program.



I’m not against the idea, just looking at it from Rachio’s side and why it may not be as clear-cut as a win as we’d like it to be.

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@scorp508 You hit the nail on the head- it feels like an easy fix, and then these wrenches keep working their way in and blowing up the solution :joy: Regardless, the amount of activity on this thread (and many others) makes it incredibly clear that our current solution could be improved.

Interesting discussion. I’ll add one more degree of complexity. For my (pathetically small) yard, I need to use a series of smaller nozzles to cover the yard that lays beside the garage (approx 1.5 meters wide, stretching around 8 meter). I’m sure a lot of people have areas that require additional nozzles just to cover oddly shaped parts though. That means either adding even more zones to the plan, or adding nozzles with different sizes to one zone.

I’m just going to read the water flow meter :slight_smile: But do we have a setting to adjust actual water usage in the app then? Or is that still a feature request?

There are 2 basic approaches to measure or calculate water usage - using precipitation rate x area, or using gallons per minute. Both approaches can be either measured or estimated using manufacturer’s nozzle specs (perhaps adjusted if you know how much each nozzle was adjusted).

Of course a measurement is better than an estimate. I have a water meter, but the city reads it electronically every 4 months, so I can’t get a real GPM measurement from my meter.
I would only go to the trouble of setting up catch cups to measure precipitation rates if I wanted to adjust my nozzles, not just to measure flow for rachio stats. However, it might help me tune my flex schedules.
So, looks like an estimate for me. None of my zones are perfectly rectangular, and none have all heads with the same flow rate. Many of the nozzles are variable arc, so the flow depends on the arc. Some heads may have had radius reduced, so flow would be less. I can estimate the GPM flow from each head and add up the total flow for the zone.

I am not a fan of having the precipitation rate defaulted by nozzle type, instead I would enter it zone by zone. I bet that most zones have odd shapes, irregular head placement or imperfect head coverage, so the manufacturer specified PR is not achieved. However, the efficiency for the zone can be reduced for irregular zones.

I think the product suggestion is to have total zone GPM, Precipitation rate and zone area as 3 zone parameters. 2 must be entered and the third is derived by Rachio, using the other 2. The user can choose which 2 will be entered, and which will be derived.


I have one zone that fails to meet any sense of decency to the way it was laid out due to both the irregular area it tries to cover as well as the number of heads jammed into the area for both itself and neighboring/overlapping zones. It also has very varied coverage along its perimeter compared to in the middle of its field. Perimeter cups catch <10ml over 10 min while center field cups catch 16-20ml once the zone and overlapping zone are run. I’d welcome the ability of doing some kind of per-zone override for GPM, but at the end of the day I think that particular zone is going to be all about compromise. :slight_smile:

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I really like the idea of users being able to choose which they provide, and we back into the third. That way users are entering the two they are more comfortable with, and hopefully hey are more accurate!

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I did not read all of the above, but when I installed mine, I did the "Log meter reading, run for 5 minutes, log meter, run next zone for 5 minutes, etc.+ then just created new heads with custom PRs. It’s not perfect, but much closer than out-of-box. That said, if the software, DURING SETUP, simply asked for a meter reading before each zone fired, it could do all the math for us and make the product much more user-friendly and SIGNIFICANTLY more accurate.
NOTE: This assumes the owner has access to the meter.


Yes, this is perfect. It is a very good way to calculate PR. Here is the Rachio support article:

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Right. I have 10 zones. It was a pain to sit by the city water meter and operate each zone for 5 minutes and then create custom nozzles with the PR for each zone. But just today I audited the subsequent meter readings versus Rachio and they were in good agreement. Kudos to Rachio for making this possible and reasonably convenient. Now I can manage my usage with confidence.


Even though I’m on well water I’m starting to feel like a meter would be a nice thing to still have.

If you Google flow meters for well water, you can buy one for about $100. They are basically totalizers like the water meter your water utility uses. I would recommend having a plumber install it. But it would have no connection to the controller. You would take readings to record usage.

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EBay has meters with 1/2in couplings for $30 and 3/4in for $40

Ebay concerns me. I am skeptical of ebay.


Of course it’s your choice. I have three installed measuring different aspects of my rainwater collection system for about two years now and they are doing just fine. I buy a lot of stuff from eBay but I agree that if the price is too good to be true, it probably is a scam, you need to be sensible.

Love this suggestion.

Ever since joining this community and buying my Rachio, I’ve wished I could specify how many heads were in each zone. Haven’t read through the entire thread yet but I’m glad you suggested it.

Best Regards,


I recently had to install new main lines for my back yard due to a tree being planted over the lines decades ago. I found one zone that had 8 heads on it still under performing. After many hours of researching Rain Birds site, I found their flow/coverage charts. Taking the nozzles from U15’s to MPR12’s (calculated by head spacing), I was able to reduce the consumption by roughly 8 gpm. So, being able to add the amount of nozzles per zone and flow rates would be very helpful. Also, Rain Bird actually gives you flow rates for different PSI’s (dynamic pressure). Dynamic pressure is easy to read by hooking up a gauge to your spigot, turn on the system, and voila, a dynamic pressure is read. Interestingly enough, the difference between a 12’ and 15’ nozzle does not change the PR, but does change the flow rate by 1 gpm. This would be nice data to be able to input into the app for increased accuracy.

BTW, my local irrigation company suggested to leave the set screw flow controls wide open on the nozzles. If you have the right spacing and nozzle, no need to adjust.

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I think number of nozzles would probably just make the system more complicated than it already is. How are the vast majority of users going to calculate the flow rate on a single head? Most don’t even know what model # their heads are. If anything they need a casual user interface and a irrigation expert interface. I can see already that there’s far more to it than I anticipated, but I’m somewhat of a techie (my profile pic is ironic) and I’ll figure it out. Seriously, how many systems even use flow meters. I’m wiling to bet that most people that install this unit are (like me) upgrading their old dumb systems just for the smart watering feature based on weather. My system will run for the first time tonight since I installed it 6 weeks ago because of all the rain we’ve had. I haven’t had to turn the system on and off over and over again like I have in the past because of forecast rain. I love it, but most people have no idea what the flow rate on a zone is. I assure you the casual user setup would be used by the vast majority. For the most part number of heads are really irrelevant. What’s relevant is the amount of water being used per minute over a set area for the zone. That’s what calculates X inches of water. The casual user just wants a button that says this zone is getting too much water or not enough. I feel like all the requests for more features are coming from irrigation professionals just to create job security. :wink: