Add Number of Heads on a Zone for Accurate GPM

Here is an idea to gain more accuracy on gallons used. I have realized the gallons used is meaningless because there is no way to input the number of heads on a zone. Each head adds additional gallons per minute. This would be a easy software upgrade. Go further, if there was a way to input pipe size, Rachio could provide a hydraulics alert for too many heads on a zone.


Great suggestions, something I had been wondering about this myself lately. I found this page: that indicates they use the square footage of the zone in the calculation, which as you point out is irrelevant.

I’m going to pump more water onto the same zone if I have six nozzles than I would if I have four. Also if I measure my zone and find it is 1000 sq. ft. instead of 500 default value, then updating this value in the settings will not actually double the amount of water I am providing the zone during a watering cycle, as would be indicated by the formula in use.

So yes, I would really like to see Rachio add a setting for number of nozzles as well as some type of warning for having too few/many nozzles in a zone. In the mean time setting the zone size to the number of nozzles would fix the usage settings but would likely bork the other calculations required for the flexible watering schedules.

Perhaps a functional compromise would be to set the zone area to the number of nozzles x 100. For the average homeowner, at least in my area, that would likely be somewhere around the 500 sq. ft. default setting in most cases. Allowing you to calculate water usage by simply dividing displayed usage by 100. Though again, I do not know how that would impact Flex Schedule calculations, so I wouldn’t make changes to my system without some input from Rachio.

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The square footage is relevant when estimating water used and that is it.

This is tricky and a sticking point with a lot of ppl, some pretend it is easier than it is.

The tricky part is, and I’ll do a horable job articulating it, nozzles mean nothing. I can take the same nozzle that flows at 5gpm and provide a nozzle that will increase the pr but shrink the coverage or decrease the pr and increase the coverage. So now you are thinking, doesn’t matter, 5gpm X 4 nozzles is 20 gpm using area we can get a pr, so who cares, and I’ll agree for the sake of argument. The issue arises when you take into account head pattern. You can follow a square pattern or a triangle pattern, with the same number of heads this will change the pr of the yard without changing the quantity of water applied or the number of heads, so a flex daily schedule will perform differently for all of the same values except nozzle placement.

You could account for the pr difference by adjusting the efficiency of the zone which indicates how uniform the water distribution is, thus flex can over apply water to ensure that lower pr areas reach their saturation. But now you have provided a setting that is a fuzzy setting, you are still stuck with using catch cans to compute the pr of multiple spots in the yard to provide an accurate value for efficiency, so you just dragged an accurate pr measurement back into reality, thus escaped nothing.

Now let’s consider the tolerance to the system. if you are looking for accuracy, you will need to measure the psi at the heads and plug that value in as that will have an influential impact on the actual flow rate of the head.

So I will agree that nozzle count with gpm will work on a wasteful schedule like a fixed, and could be implanted for that specific but will be very counterproductive for flex.

Now here comes a curve ball, in 1 spot of my yard I have a 3gpm head with 4 5 gpm heads. I have to do this to keep my efficiency high, so technically this solution would lie in this setup by 2gpm of every active schedule minute which would be 30 gallons a cycle over 7 cycles in August on a single zone. Maybe inconciquential, just another data point.


Okay, I will freely admit my prior statement was highly oversimplified however I respectfully disagree that the efficient my sprinkler coverage impacts water flow rates. How much time I have to run the system to effectively cover the zone yes, but not how much water is actually used. I can for example adjust a set screw to alter the spray pattern of my sprinkler heads to be a tight stream and cover a fairly large distance or be a mist and cover a very small distance, regardless the head is still flowing the same amount of water even though I have significantly altered the coverage area. You have articulated another weak point in the usage calculation though, that it is assumed all heads in each zone have the same flow rating.

Catch cans are very useful for finding how much water is getting to specific area’s of a zone but that still doesn’t tell you how much water is actually coming out of each head. I do not have a degree in fluid dynamics so the science and math of it are beyond me yet it seems logical to me that available water pressure at each head, the size of the supply lines, the number of heads and how much they can flow given those values as well as watering time determines the amount of water actually used. It seems illogical that the size of the area being watered impacts that value and the only impact related to efficiency of coverage would be for watering time that is required to adequately cover all areas of a zone.

I am not looking for an exact number but I would definitely like to see a more accurate representation of the amount of water I am using for my lawn each event, month, season/year.

My whole point is providing a more accurate accounting of the gallons that flow through the water meter. This is what we are billed for by the utility. I care nothing about the square footage, only about the total flow of the zone. Its that simple. Hydrorain and Orbit have an input for number of heads on the zone.

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Sorry, that is not what I meant, I told you I’m not good at this articulation thing. I agree with your statement, I think what I was trying to say that water pressure effects gpm. I was also tying to state that head placement will effect pr which will cause flex daily to under/over apply water.

It doesn’t tell you how much is coming out of each head, but it DOES tell you how much is coming out of the system when you adjust for efficiency and account for square footage, we can have that discussion if you like on a different thread…accuracy of the gallons used increases with the accuracy of the efficiency and pr, asymptotically.

Yes, I understand, I just keep trying, victoriouslessly to illustrate how it is nowhere near as simple as it commonly presented, to make this type of change, it has a 100% negative impact on some other part of the system as a whole, a large percentage of the customer base will be impacted either way, it’s a conundrum.

As I said, I think it makes sense as an option on a fixed schedule only, but currently seems impossible to accommodate pragmatically for a flex schedule.

I apolgize, I know I’m stubborn on this issue as well as landscap lighting In rachio. I’m not an employee, I’m just loyal to their pragmatism, and the answer is not upon us for the reason I have mentioned, the are not excuses, just reality. Who knows, maybe they have solved it and we don’t know just yet.

the true approach to tolerable water accounting is a flow sensor. Trust me when I say, I was in your boat, if I go 1 gallon over a limit I will, and have, received an additional $250 penalty on my bill for the month. I’m very sensitive to this subject. That’s why I installed a fsi-t10.

I promise, I will never comment on this or lighting again, the horse died last season, I should stop kicking it…

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No worries, I was just admitting to the fact that it was an oversimplification on my part and I recognized it as such.

As for the rest of it, I appreciate the discourse it is definitely educational, the rub is that the settings are all interrelated. Changing one setting to try and make something more accurate affects 2 or three other things. Nature of the beast.

What I was trying to articulate, as I understood the OP and per his followup, was that I would like to see a semi-accurate representation of what gets pushed through the system in addition to what actually hits the ground given the information I have entered into the interface. I believe both can be accomplished with relatively ease on their part.

Again I appreciate the information you provided, it caused me to revisit my settings and see if there was something I should change.

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@imatechguy, great idea and discussion. The difficultly with this concept is the combination of inputs and variables that affect the sum of the whole. Every head has a nozzle that can have a different GPM or GPH rating, which can further vary based on spacing and/or head adjustment. From a scheduling perspective, each nozzle’s output needs to be considered (as well as it’s coverage distribution) to convert into an input that can be used for scheduling. As such, we use the precipitation rate of the zone (flow output of all heads) when scheduling. We don’t assume all heads have the same flow rating; rather we set a default efficiency (distribution uniformity) to account for these variables.

Just curious, how much data would you be willing to enter into your zone settings to capture this number? Assuming you’d need to enter the number of heads for each zone and/or conduct a catch cup test for each zone, which could take 15 minutes/zone, is this a time investment you’d be willing to make on a seasonal basis?

Alternatively, would you be willing to provide other data inputs? i.e. Water Meter photos, utility bills, etc?

@robertokc, I’ve seen this input in their app. When I check the advanced settings, the Application Rate defaults to 0. I haven’t added catch cup data to the zone, so it may default to zero unless you override it. Perhaps you can provide more context from experience. Curious if you have an opinion on accurately of schedules between the two scheduling models?

Agreed. A flow sensor is the best solution for tracking usage and eliminates all guess work.

@imatechguy, this is effectively the difference in gross and net precipitation rates, which will require a catch cup test to accurately measure. The settings in the app were designed to get you as accurate as possible with as little work as possible. Open to feedback, but I believe the usage estimates in the app are probably fairly accurate to what your system is doing if you’ve provided custom inputs for all of the advanced settings on a zone by zone basis…


Everybody already has a flow sensor! Why not just take a reading at the water meter, run a zone for a while and then take a second reading. Subtract the two and then have a way to adjust the consumed estimated water in the rachio software? No counting heads or anything. The question is, what can you do with that info? Is there a way to adjust the schedules to limit water use?


This would work, but utilities discourage getting into the meter can. They own the meter. It is in their easement.

I have used the Orbit/Hydrorain B-Hyve in a test, utilized their catch cups and entered the number of heads. This product won the Irrigation Association’s New Product Contest. I was one of the judges in Las Vegas. I still like Rachio better, since I dont know where their weather data originates. I would say their product is more user friendly for contractors and homeowners because it has dials and buttons on the faceplate. I think people are trying to make this flow estimate more difficult than it needs to be. Most homeowners are clueless.

In the many hundreds of homes I’ve built, I’ve always had to purchase the water meter. Maybe it’s different where you are but I can’t imagine they discourage you from reading the usage off it. It’s​ how everyone agrees on the charges.

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You may think you are purchasing a water meter, but you are actually paying for impact fees and for the utility to set and install the meter. The utility owns the water meter. Its in their easement. The impact fees and the monthly service fees are based on the size of the meter.

The meter cost is usually $500 and the impact fees are $5000, then connection fees $4000, standby fees etc; which is rather off topic. The point being, telling people not to go in the meter box is absurd. Otherwise there’s no point to having a meter. Just let the city send a bill for whatever they want.

Using the meter to measure zone consumption is going to be the most accurate way to figure your usage or bill. It even accounts for an inaccurate meter.

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Come work for a water utility and you will get a new perspective about homeowners messing with their meter. Not meaning to be a smart alec.

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FYI, meters can be inaccurate after many years. They underread gallons when they get older. Its never the opposite. This is why utilities have a meter replacement program, so they are reading accurate flow. Still the meter belongs to the utility. A utility can lock a meter or pull a meter for nonpayment.

Not mine. They encourage us to use the meter readings for events just like this.

Nothing wrong with meter readings and checking/measuring flow, utilities just dont want people tampering or removing the meter. Licensed plumber for irrigation tap.

I like the idea of using one’s water meter to gauge water usage per zone. I figure we can run a each zone for 60 seconds and record the consumption per zone. Then add them all together and multiply that by the programmed run time. Or, perhaps record the meter reading before starting the cycle and then after and multiply that by what the water company is charging.

Would be nice if there was a sub app in the software to let us do something like that on the first run, then let the software tie it to dollars based upon what our utility company is charging per gallon. We then have a steady idea of what we will be expecting with the quarterly bill comes. Is this possible?

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