Author Topic: Open Valve for the Day based on Past Rainfall  (Read 348 times)

Offline mswlogo

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Open Valve for the Day based on Past Rainfall
« on: June 01, 2017, 01:23:37 pm »
How hard can that be?

Seems like such a basic function that could be combined with a simple timer based system.

I run 6-8 timers for Garden and Lawn.

I don't need to analyze soil or plant types. I just water each section 20 minutes a day and all is fine. My Tomatoes are usually 8 feet high and I need ladder to pick the cherry tomatoes.

I don't want an Irrigation System. Doesn't work well with Garden. Also if installed in lawn it raises my Tax Bill or Water Rate (I forget).

The Timers have worked great for years. But it is wasteful. I try to turn them off if things are wet or will be wet. But sometimes I forget and leave it on or leave it off.

Water Moisture meters are not right for this. You want things to stay moist all the time. It's really based on inches of water per week. And you really want past precipitation to be factored in (more than future forecast which is not always reliable, but past should be).

I shouldn't have to install a rain gauge to make this work.

So how much work would this be to make work on Vera, or any other home automation system.

I'm tempted to buy a Irrigation Controller that does exactly this, add a sensor to the output valve and if that is on, then open the valve :).

But that seems a bit silly. Gosh this shouldn't be so hard.

Suggestions?



Offline kwieto

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Re: Open Valve for the Day based on Past Rainfall
« Reply #1 on: June 05, 2017, 04:17:02 pm »
Gardena offers a system where you can attach moisture sensor and/or rain gauge.
If it is based on inches of water per week then rain gauge is the best choice.

By the way I think that moisture sensor is most accurate solution - you want to keep things moist all the time but I think there is difference between i.e. 10% and 90% of the moist level.
So basically you set the system to turn on if moist level drops below the limit you set and turn off if it goes above another limit. That way you keep the same level of water in the ground regardless of rain, temperature, ground water level and other factors which can change the moist level.

If you don't want to install any device, you have Virtual Rain Sensor plugin which should do the job you want.
Just remember that real and predicted rain are not the same thing and it may happen that according to the weather forecast it should rain when in fact there won't be any drop.