How Do I Reduce Watering from Defaults?

I am of the opinion that my system is over-watering a bit. I would like to reduce the watering amounts gradually to see what my landscape can handle. What is the best way to adjust the system using Flex Daily programming?

Make sure the shading and soil type are correct for your area

Are you using drip irrigation, bubblers, or sprinklers? This value will determine the correct nozzle inches per hour

What plants are you watering, such as trees, shrubs lawn etc? This will help determine the correct crop coefficient and root depth.

Thanks. I’m using drip, bubblers, and sprinklers in different places. I am watering trees, shrubs, lawn, succulents.

I appreciate that Rachio attempts to adjust according to how I describe all the variables, but I still want to be able to reduce watering from what Rachio concludes is best and to see if my plants tolerate lower watering. Any idea how to do that?

I would reduce the crop coefficient to reduce the amount of water per plant. What are your current crop coefficients for each plant type?

Thanks for this. The crop coefficient is at the default for each. In searching on that term, I found this Rachio page, which seems to answer my question.

What is interesting is that it appears that you can reduce the amount of time of the watering, while leaving the frequency the same; or by using the crop coefficient you can decrease (or increase) the watering frequency, but leave the time the same. I’m going to have to think about what would be best to adjust.

If you know the flow rate, and it’s correct, change the crop coefficient to keep with the principle of deep and infrequent watering.

If you are guessing with the nozzle inch per hour, you might be underestimating the true nozzle inch per hour. You could adjust the nozzle inch per hour up to decrease the runtime, without changing the crop coefficient.

Thanks. I am not seeing on option regarding precipitation rate? I think adjusting the crop coefficient should do the trick.

I meant the nozzle inch per hour. It’s called the precipitation rate for some sprinkler nozzle manufacturers

I agree that decreasing the crop coefficient is probably the better way to go assuming everything else is programmed correctly.

You need to change only one thing, so you can properly evaluate results

If you choose to amend the co-efficient, Lowering will starve the grass of water, which is what you want to do. It will end up increasing the duration between watering cycles.

Alternatively, increasing the nozzle inches per hour tells the system that you are putting down more water than you are, meaning that it will reduce the duration of watering each time.

You could / should calculate your correct, exact, nozzle inches per hour by running a zone for maybe 5 or 10 mins and take the quantity used off meter readings and then calculating with (Quantity / Area / Mins) * 60

Thanks. Yes, as alluded in an earlier post, I am watering a wide variety of things including (mostly) succulents, as well as areas with trees, grass, and shrubs, mostly on different stations. The grass I am leaving as-is. Rachio seems to have this more or less right. But for the others, it seems to over-water. Therefore I am reducing the co-efficient from the default of 30% to 15% and will see how it goes.

I don’t completely trust this chart, but it might help you adjust the crop coefficients and nozzle inch per hour. Don’t decrease the crop coefficient too quickly. It might stress the plants

Thanks very much for this. Really interesting and useful that Gilbert does this. I have a friend in Gilbert, so I know the area pretty well. I’m in San Diego near the coast. Obviously, this is a less dry climate compared to Gilbert, although annual rainfall is somewhat similar. We have a pretty good sense of how often we want our succulents watered and for how long. By adjusting the crop coefficient by 50% we can see that the watering frequency changes to about 2.5 weeks. That’s basically what we’re aiming for and how we had the prior controller set up. Seemed to work fairly well. My sense is that the Rachio doesn’t adjust for local climate, per se, but for things like sun and measurable precipitation.

There are a lot of variables that go into calculating water needs. it all starts obviously with the right inputs. Crop coefficients and Precipitation Rates are two, Xeriscape and Native Trees can be as low as 30 to 35. You will have to adjust for each emitter type and soil. Drip, spacing of the emitters and spacing between the lines as well as the GPH all need to be designed based on soil type and zoning or microclimates really prior to install to determine the actual precipitation rate.