Multiple sprinklers in one zone - and is there a Test System?

Hi all,

Can zones be setup with several sprinklers in the one zone ? I have several zones with maybe 10 sprinklers in each zone, with sprinklers about 3m apart. From what I am reading and seeing on videos, am I correct to say that the system can calculate the amount of time that a section should be watered, based on the area and soil type and air temperature and weather ? You you specify the number of sprinklers in xx sq.m ?

Is there any access to a test / simulation system that I can setup my location and see how zones and soil types are selected and see how well it would adapt to weather. I am planning the installation for southern Spain

Thanks in advance

I wasn’t going to answer either, but since no one has…

Multiple sprinklers on one zone is fine, and in fact pretty much always the case.

I was going to mention Flex Daily, but I’m not sure the data is available everywhere for Flex Daily, and as you’re in Spain, I’ll let that go for now (someone else may know if local weather data is available through Rachio in Spain).

When you set up a zone, you select the Soil Type (which determines how much water per inch of soil it can hold) and the type of Crop/Grass (which determines the Root Depth & Crop Coefficient). Sun setting helps determines how much water the plant uses, and slope & soil determine how quickly the soil can absorb water. This missing piece, and IMHO sometimes the hardest to get, is the Nozzle Inches per Hour. That is chosen based the type of sprinkler head being used, but there is a LOT of variation in the real world from the standard values chosen by Rachio.

After setting the zones, if you know about how many minutes of watering for each zone per day/week, you can always set up a Fixed Schedule by entering those minutes.

If you’re using Flex Monthly, which should be available to you (unlike possibly Flex Daily), then setting up that schedule will tell you how long each zone will be watered, and how often. That’s the closest thing to a test or simulation: does that number of minutes and frequency sound okay. If you need to know the actual water Rachio thinks it’s applying during that time, we can help calculate for for you if we know your zone factors (I’d want to know, but maybe you don’t need to).

I mentioned earlier about getting the correct Nozzle Inches per Hour (which is the total water applied fairly evenly over a zone in an hour and has nothing to do with actual nozzle output). If you can water your lawn for a period of time, and measure the water used (by water meter) and calculate the area of the zone, we (I and other users here - I’m not a Rachio employee) can help you come up with Nozzle Inches per Hour that may be more accurate for you.

Hope this helps.

Many thanks for taking such an amount of your time to provide me with such a comprehensive reply.

Let me explain a bit more about where I’m coming from on this, and where I’m trying to get to.

I am a VP of an apartment complex in Spain. We have large gardens with many zones, with between 8 and 12 sprinkler heads per zone, which are watered every second day, between 01:00 and 04:00, for 20 mins. No two zones activate simultaneously, due to the large amount of water used by each zone each time. So annually, water costs us a small fortune.

So the objective is threefold.

  1. Stop watering (or reduce the 20 min period) if it is raining, or if it has recently rained or will rain soon, and based on if it was pouring rain or just light rain.
  2. Hopefully automatically calculate the amount of time that the grass SHOULD be watered for, since I believe that the watering currently is excessive.
  3. Dynamically adjust the length of time of watering for different times of the year (although this may just be based on the air temperature at that time ?)

Attached is a photo of the gardens

Beautiful grounds. Love the pool shape. Maybe I should make a reservation. :wink:

I prefer watering early morning rather than during the night, but understand that with public gardens, you don’t want to water during the day.

Provided the number of zones with your Rachio (8 to 16) is sufficient, then it will only water one zone at a time. And yes, I can only imagine your watering costs.

The Flex Monthly and Fixed schedules have the Rain Skip feature, which skips watering if you’ve just have or will have rain. Flex Daily can do that and more, but not sure if you can use it.

You mention watering every other day. Are there any watering restrictions (days, hours, etc.) you have to obey?

All the schedules, based on the soil and grass type, will calculate the amount of time required. The only real variable is how much water your system puts out per hour to the grass, the Nozzle Inches per Hour. Catch cups would be a real chore with a very large system, but you may be able to accurately calculate areas for each zone, and measure water usage for a given time using a water meter, and we can help you calculate the right value based on your readings.

Flex Monthly schedules automatically adjusts the frequency of watering based on historic temperature data for the area. Fixed schedules can use the Seasonal Shift feature to adjust both frequency and duration

Flex Daily is the most accurate, as it uses ACTUAL temperatures and actual rainfall based on nearby weather stations, and gives you graphs to show the moisture levels of each zone. Keep in mind that with Flex Daily and Flex Monthly, especially with grass zones, the idea is to saturate the grass in the zone, then wait 2-10+ days, depending on temperature, rainfall, etc. letting the grass dry out about halfway (50%), then water again. That helps force the roots deeper during the drying times and is good for the grass. I’m not certain it results in the best looking grass all the time, but I think it’s pretty good and I use it.

I think I’m getting a bit too specific, given you’ve posted in the Before You Buy area of the forums. So, I’ll say this: I think the features of the Rachio should work very well for your conditions, avoiding watering when you have rain, and keeping the grass in good health, provided you can take a bit of time to “calibrate” the system (especially a system that I think is going to be a good bit different than the normal home system), provided you don’t have more that 16 zones (although 2 Rachio controllers can be linked somehow).

The main question to Rachio, really, is "Is weather data, historic and current, available in Spain, and can Flex Daily, Flex Monthly and Seasonal Shift work in Spain? I see you have Weather Underground stations in the area, so that’s good.


Thanks again for the fantastic feedback. I’ve a Weather Underground PWS about 2 miles away - Mojácar (IMOJCA1) - so will that be used by Flex Daily ?

The whole irrigation system has it’s own water meter, measuring the water in cubic meters. About two years ago, I tested all zones because I wanted to check if we had any leaks. So I ran each zone for 2 minutes, and measured the usage for each zone. The usage So if I still have that data, I can calculate the usage per zone per hour. However, I see that all sprinklers be they rotating or static directional with 90 deg coverage, appeared to deliver an average of 10 litres per minute - so 600 litres per hour.
So you can see why I was going crazy at watering for 20 mins !!!

We have no local restrictions. We’d possibly want all watering to be completed by about 07:00 at the latest, since people could be up and about. We could start around 04:00 when there’s less chance of people sitting or terraces when their gardens are being watered (see addition pic below)

The garden I pictured actually has 11 zones, so a 16 zone would work for that. However, we have another large side area (down the end, out to the right) with another 6 zones, so that would would take an 8 zone controller. We have wifi around the pool, so that will reach the 16 zone unit. But can the 8 be linked in some way to the 16, since we don’t have wifi coverage around the side area ?

It certainly seems that the Rachio 3 is the solution for us.

Most of the features will work as planned, Gen 3 controller will be able to get rain data from your local WU station and use that data to keep track of moisture levels in your zones (in case you use flex daily schedule).

That being said, Rachio (at least for now) does not use WU data to calculate evaporation (loss) data, instead Aeris (pwsweather / NOAA) network is used. This is the part I do not know, how accurate is the evaporation data will be in your area.

Keep in mind, actual evaporation accounts for a fraction of losses Rachio is tracking. If you set the right plant & soil settings, any errors in evaporation will likely be negligible.

You will still get the major benefits of weather tracking (accurate account of rain), even if evaporation data may not have been tested / intended to use in your area.

While Aeris does not have Mojacar, it has Carboneras, Spain, which is just less than 10 miles away, along the same coast. So will the system try to pick up something automatically, or do you enter it manually ?

And are all manuals / instructions available in Spanish ? I know the local gardiner does not really speak english

No problem. Glad to help.

As Gene said, Rachio will use that station for rainfall only (the most important factor, really). So Flex Daily would use that.

Yeah, that’s a lot of water. In any event, with your measured usage and your zone’s square feet (Rachio can probably accommodate metric units), we can measure your average Nozzle Inches per Hour for each zone.


You can specify a time to complete the watering as well, so use your 07:00.

I don’t know of a way to link them without WIFI to both. Perhaps one or more repeaters to get the signal to the other unit? And you’ll have to get advice from someone else as to how to set up 2 Rachios to work together; I have no experience in that.

It sounds like it could be. Gene mentioned about the accuracy of the weather information used to calculate the daily water requirement of your zones. That’s very important with Flex Daily. You could probably locate some accurate local FRET or ET information that you could compare to their figures. Adjusting up or down isn’t a problem, but if the weather information isn’t related well to your actual weather, you’d be better off with Flex Monthly or even Fixed schedules.

And are all manuals / instructions available in Spanish ? I know the local gardiner does not really speak english

Just to say, I now have my 16 zone controller. Rather than getting a second unit and extending wifi, I’ll get someone to extend the wiring from the second point back to the first, and run everything off the one Controller. We have installed our own PWS too.

So I am stuck @rraisley on the value needed for the nozzle cm/hr. If I take it that all sprinklers are simply the one average type and spraying 10litres/min, how does this equate to nozzle cm/hr ? Is the Area setting purely for calculating the possible volume of water consumed ? I don’t see anywhere to maybe set the number of sprinklers in a zone. But does this really matter ?

I was concerned if one Rachio would handle it as I thought the 10 l/h might have been for the zone, and it would take too long to water. But I now realize from your specs that it’s a high volume commercial unit, so that shouldn’t be a problem.

Well, cm/h is always a sticking point, being rather hard to find. I find catch cups burdensome and prone to error due to placement. An /average/ is easily obtained by taking actual flow per hour and dividing it by square feet (plus other factors), so IMHO it’s worth the time to measure.

Precipitation Rate (PR) and GPM is easy to find in any manufacturers’ product catalog in both US and Metric Equivalents. It’s not a misnomer, and when using Rachio defaults you can easily adjust the settings. I do it everyday and have to, which makes customizing watering efficiency in the landscape a strong fist winner solution to every situational environment.

Hence, inches per hour is relevant and not some obscure magical facet with regards to output of an emissions device. It has everything to do with it and it’s tested. Those tests and the algorithms is how Rachio , or any smart controller or modeling program gets it information. Knowing the GPM , PR rates give an irrigator some base to be able to make adjustments for best application methods in the field, manipulating rates, radius and flow
with any manufacturers product.

image chapoinc, there is a “test/simulator” program that I plug in landscape and sprinkler device variables to use to justify my scheduling data for consulting or presentation. I have mentioned it previously.

If you PM me , I can hook you up with that and we can reach out to any major manufacturer of irrigation products that you have installed on your site.

Thanks and welcome to the Rachio Family!

Thanks for the reply. I have absolutely no idea whatsoever as to who the manufacturers of the nozzles are and I even looked at the Rain Bird products catalog and there are so many different nozzles for even the same pattern, so it’s certainly not very straightforward as I would have thought.

Anyway, rraisley has helped to work out my aproximate nozzle sizes from my water consumption, and I am experimenting with various settings on my controller which I now have testing

Where are you getting 10 liters per minute as your unit of measure? Per sprinkler head at 3 M intervals @ 90 degrees? That’s ridiculous. Your calculations, flow and rates are askew somewhere.

The manufacturer stamps the Radius of Fixed nozzles into their parts, the arcs are usually there in graduated lines. You either have female threads or male threads. Take a picture, ask your Gardiner what’s in each Zone that you should have a map for let alone an invoice for replacement parts.

@rraisley “An /average/ is easily obtained by taking actual flow per hour and dividing it by square feet (plus other factors), so IMHO it’s worth the time to measure.” Really???

Man aerospace engineers really, but a spin on things…

You guys are guessing, and making things harder than by first starting to look at the parts that are in the field, and the book by the manufacturer that has the specifications in it. Then use Rachio, to adjust the modeling defaults it has for Zones, Plant Type, Sun, Soils, PR, etc. geesh!

[quote=“ProWater, post:15, topic:27813”]
@rraisley “An /average/ is easily obtained by taking actual flow per hour and dividing it by square feet (plus other factors), so IMHO it’s worth the time to measure.” Really???[/quote]
Yup, really. FAR more accurate than using manufacturer’s specs without knowing actual pressures at each head, or adjustment, etc… Manufacturer’s specs are completely worthless on my lot, which is possibly why the advice of all the so called experts has been worthless as well. Flow > Area > Done.

We rocket engineers are a different breed, but we know when to measure actual results and not rely on theory only.

I disagree. Using manufacturer specs is doing the guessing, because they rarely occur in real life, and even when they do, they require a lot more measurements and such than I’m doing. I’ve compared the specs versus what I’m getting, and they’re nowhere near the same. So I choose the easy, more accurate way.

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While Aeris does not have our area of Mojacar, it has Carboneras, Spain, which is just less than 10 miles away, along the same coast. So will the system try / be able to pick up something from Aeris automatically