Weather adjustment for weekly watering

[marcusb]

Hi,
I would like to water the lawn only once or twice a week, not daily. However I’m unsure how this would interact with the weather adjustment features.

Reading about the ETo algorithm (https://openthings.freshdesk.com/support/solutions/articles/5000823370-using-weather-adjustments#ET), it seems to take into account only the previous day’s conditions. That is clearly insufficient if you are watering once a week – it would have to account for total rainfall over the past week to do the right thing.

Is there a way to make this work?

[Underpaid1349]

I’d love you know if you ever figured out a solution or adjustment to make less frequent watering work. I’m anticipating needing to do the same (2-3 waterings per week) for my fescue.

[Ray]

To customize the weather algorithm, you can either run the weather script on your own server and direct your opensprinkler (use the /su page) to your own weather server, or you can run a local server and send command to opensprinkler to change the watering level periodically.

[Underpaid1349]

Thanks for the response, Ray. I took a look at the project you mentioned.

I’m guess I’m out of my league right now trying how I would change the eto weather adjuster. I looked through this file (https://github.com/OpenSprinkler/OpenSprinkler-Weather/blob/master/routes/adjustmentMethods/EToAdjustmentMethod.ts) but nothing really jumps out as a feasible stateful way to accumulate eto data over a configured period of time.

Is it possible as a future feature to calculate eto from when a program was last run, or a set number of days? E.g. if I only have it set to run twice a week for deeper watering of tall fescue. Then the program could identify when it was last run to know what the current eto should be.

Or I guess a better question; What would you do if you were in my position trying to set up a residential irrigation schedule for a lawn that shouldn’t have daily waterings? I’d like to utilize tools that would make these weather adjustments in a smart way.

Thanks!

[Ray]

I honestly don’t know if there is one correct way to implement this. A slightly easier version is probably to get the watering percentage every day and calculate an average across several days and use the average number for the day watering is enabled. Another way is to calculate the average of weather parameters and compute ETo using the average weather parameters. I am not an expert in ETo, so I honestly don’t know if there is one correct way to implement this.

[Chester Corcos]

I think that’s a good idea, Ray. This will require an update to the firmware though, not the weather api. The controller needs to keep track of the evaporation every day and then when it comes to water, it will simply calculate how much has evaporated compared to the baseline – an average would work just fine. This is a much better way of doing this…

[Author]

Posts