Advanced settings doubts (metric system)

Hi, I have a couple of questions about properly setting up my zones advanced settings on my new gen. 3 Rachio:

  • I live in italy, so I’m using the metric system. I have a single long dripline that is watering my hedge (shrubs). The nozzles are each one 33cm apart (12,9") and each plant is, on avg, placed 75-100cm (29,5-39,3") from the others, so on avg each plant has 2 nozzles in its proximity. The nozzles have a flow rate of 2 liters per hour (0,53gph). For the “Nozzle cm per hour” I have calculated that for each sq meter (linear meter?) I have approximately 3 nozzles emitting 2cm (1 cube meter is 1000liters) per hour each one, so this adds up to a value of 6cm per hour (2,36" per hour per sq m). Is the calculation correct by assuming a value per square meter (even on a single linear dripline?) or should I consider a value per square ft, even if I set up the controller by using the metric system?
    It seems a bit too high, maybe I did something wrong in the math. Currently I’m using half the value because, in theory, no plant has all 3 nozzles very near.

  • My second doubt is on setting the right area of my lawn. It has been divided by my gardener in 2 physical sprinkler zones, one is covering the NE part and the other the SW part, even if it’s still a single piece of grassland. So I have 2 different zones on Rachio, but the solution is not that bad because the second part is mostly in the shade and stays way more wet, while the first one is always in the sun, so I can set that accordingly. Let’s say that on a logical level the first zone covers 70% of the lawn while the second one the 30%. The problem is that, obviously, the sprinklers are overlapping in some points between the 2 areas, so for an optimal configuration of both zones sq meters should I consider the logical division of the lawn (so that the sum is exactly 100% of the lawn area) or the exact zone value with the overlapping (so the sum will be > 100%)?

  • As for the first question, I’ve set the lawn nozzle cm per hour with the value found in the data specs of the product, which is in mm/h (per sq meter I think), is this ok or should I consider it per sq ft?

Sorry for the long post.

Thank you,

Assuming you have even coverage, the size of the watering area does not matter, except for calculating how much total water you use. The mm/h at any given spot should be just that. If you put a catch can in an average spot, it will fill at the mm/h of the nozzle whether you use a big or small catch can. I would ignore the overlapping areas of the zones and focus getting the average area within each zone correct.

Thank you Lars, I can see your point, the nozzles are spraying evenly on the surface, so apart from the overlapping points, I think you are right and I can use the tech spec value for the lawn.

Any input on the dripline in the first question?
Generally speaking, I’ve noticed that changing the nozzle cm per hours has a great effect on watering duration times and I don’t want to underwater my garden.

If you are using drip tubing with fixed rate emitters then you input the value for how much one emitter is distributing. In the US, we have drip tubing with .6 GPH or .9GPH. I would program my controller with one or the other. Then you can tell it how many square feet or square meters.

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Yes, it’s a single line of evenly spaced drippers with fixed rate. Each plant has 1 or 2 emitters in its neighborhoods (on a 10" linear radius). Let’s assume .6 GPH for each emitter for the sake of simplicity, I should input as the value of “nozzle inches per hour”: 0.96, if I’m not mistaken.

You can set your sprinkler type to drip and it will automatically go to .5 inches per hour. That is closer for the .6 gph drip.