Irrigation Cycle Complete Question

[iostream212]

Hello,

I started to play around with the irrigation module (finally) and setup a nice irrigation program.

I have noticed, however, that my program is running daily after the initial 4 day ramp up that pushed me over my 0.5" irrigation requirement in my program. The program is:

If
       Time is  5:00:00AM
   And Module 'Climate' Rain Today is 0 "
   And Module 'Climate' Irrigation Requirement >= 0.5 inches
   And Module 'Climate' Temperature High <= 80 °F

Then
       Run Program 'Regular Sprinkler Cycle' (Then Path)
       Irrigation - Cycle Complete

Else
  - No Actions - (To add one, press 'Action')

 

And here is my sprinkler program:

If
  - No Conditions - (To add one, press 'Schedule' or 'Condition')

Then
       Set Elk Output '1-FRONT LEFT' On
       Wait  5 minutes 
       Set Elk Output '1-FRONT LEFT' Off
       Wait  1 second
       Set Elk Output '2-FRONT RIGHT' On
       Wait  5 minutes 
       Set Elk Output '2-FRONT RIGHT' Off
       Wait  1 second
       Set Elk Output '3-BACK YARD' On
       Wait  5 minutes 
       Set Elk Output '3-BACK YARD' Off
       Wait  1 second
       Set Elk Output '4-FRONT DRIP' On
       Wait  10 minutes 
       Set Elk Output '4-FRONT DRIP' Off
       Wait  1 second
       Set Elk Output '5-BACK DRIP' On
       Wait  10 minutes 
       Set Elk Output '5-BACK DRIP' Off
       Wait  1 second
       Set Elk Output '6-TREE DRIP' On
       Wait  10 minutes 
       Set Elk Output '6-TREE DRIP' Off

Else
  - No Actions - (To add one, press 'Action')

 

Yesterday values

EVTO: 0.0811 inches/day

Irrigation requirement: 0.5813 inches

Water deficit yesterday: 0.1969 inches

Today values

EVTO: 0.0799 inches/day

Irrigation requirement: 0.6231 inches

Water deficit yesterday: 0.1693 inches

 

So my questions are what exactly does 'Irrigation - Cycle Complete' do, and what does 'Reset Variables' do? Do I need to do a reset variable in combo with cycle complete?

Thank you!

[Michel Kohanim]

Hello iostream212,

 

What is your "Water Applied Per Irrigation Cycle"?

 

This is how the algorithm works:

1. ISY continuously calculates Irrigation Requirement ... this is the amount of water that has to be applied

2. Every time you issue Cycle Complete, "Water Applied Per Irrigation Cycle" is subtracted from the Irrigation Requirement (#1)

3. You do not need to Reset Variables UNLESS you want Irrigation Requirement to be reset to 0 and start over

 

So, based on what I see, I think the value for your Water Applied Per Irrigation Cycle is less than 0.5 (in the program condition) and thus the program keeps on running since the amount of water depleted is more than the amount of water you are applying.

 

Also, I am not sure why you have the Temperature and Rain Today conditions in your program. Evapotransipration algorithm already takes both of these values (in combination with solar declination, humidity, season, region, etc.) into consideration to arrive at Irrigation Requirement. I do suggest removing them.

 

With kind regards,

Michel

[iostream212]

Hi Michel, the idea for the temperature was to run a shorter cycle program twice daily if the temp was over 80 degrees or a longer program once daily if the temp was lower. The idea for the rain was to not run the sprinklers if it was raining. Thanks for the info. I will check that value as it must be incorrect. Thanks!

 

Sent from my Galaxy Nexus using Tapatalk

[iostream212]

What is your "Water Applied Per Irrigation Cycle"?

I checked this and that is set to 0.75", which is accurate for my system and set run-time. I think I will just reset the variables and watch it again. I am also having the system send me daily values via email so I can monitor them until this issue is resolved.

Thank you!

[strahan001]

I recently bought and have been attempting to implement the irrigation module. I put an e mail notification at the beginning of the water process to let me know the irrigation requirement. I then proceed to water, then have the system re-email me the irrigation requirement. As noted, the Cycle complete is supposed to subtract the fixed value set in the variable "water applied per irrigation cycle", I have noticed that irrigation requirement has not been altered?

 

here is the the sample code

 

If

Time is Sunrise - 3 hours

And Module 'Climate' Irrigation Requirement >= 0.25 inches

 

Then

Send Notification to 'Sean' content 'BeginWater'

Set 'Water Back Yard' On

Wait 5 minutes

Set 'Water Back Yard' Off

Set 'Water East Back Yard' On

Wait 5 minutes

Set 'Water East Back Yard' Off

Set 'Water East Front' On

Wait 5 minutes

Set 'Water East Front' Off

Set 'Water Flower Beds' On

Wait 5 minutes

Set 'Water Flower Beds' Off

Set 'Water Front Garage' On

Wait 5 minutes

Set 'Water Front Garage' Off

Set 'Water West Side' On

Wait 5 minutes

Set 'Water West Side' Off

Wait 1 hour

Set 'Water Back Yard' On

Wait 5 minutes

Set 'Water Back Yard' Off

Set 'Water East Back Yard' On

Wait 5 minutes

Set 'Water East Back Yard' Off

Set 'Water East Front' On

Wait 5 minutes

Set 'Water East Front' Off

Set 'Water Flower Beds' On

Wait 5 minutes

Set 'Water Flower Beds' Off

Set 'Water Front Garage' On

Wait 5 minutes

Set 'Water Front Garage' Off

Set 'Water West Side' On

Wait 5 minutes

Set 'Water West Side' Off

Irrigation - Cycle Complete

Send Notification to 'Sean' content 'WaterNotification'

 

Else

Send Notification to 'Sean' content 'NonWaterNotification'

[iostream212]

Same here. After I run cycle complete I run reset irrigation variables.

 

Sent from my Galaxy Nexus using Tapatalk

[TJF1960]

After running "cycle complete" it may take a little bit for the climate module to update the irrigation requirement...It appears to depend on the poll rate. I have mine set to 5 minutes which seems to be about when the irr. req. refreshes with the new value.

[Michel Kohanim]

Hi Tim, precisely but with one note: the actual change takes place immediately. The event generated to be sent to the Admin Console takes place at each poll (to reduce network traffic).

 

With kind regards,

Michel

[strahan001]

Seems logical.. One other question if I may.. I don't think this would ever need to happen, but I was wondering..

 

How would you program the system to actually go in a loop till the required irrigation amount was to the number 0?

[Michel Kohanim]

Hello strahan001,

 

Currently there's no easy way of doing this since things are happening based on the polling cycles.

 

With kind regards,

Michel

[strahan001]

Ok, great, one of those nerdy things I just happened to think of..

 

Now if an algorithm can be developed to forecast when it will rain so I don't water before it rains!

 

Great product!

 

Thank you

[Michel Kohanim]

Hello strahan001,

 

Actually, your question made me think so, now, every time cycle complete is called, we send an update to the UI + have programs re-evaluate.

 

Forecast is indeed on our list but we have not had good and reliable information from WB.

 

With kind regards,

Michel

[strahan001]

Ok I have been testing the irrigation module for the past few days.. After a cycle of watering is complete, the Irrigation Cycle complete is run, I am seeing that the amount of "Irrigation requirements" is apparently decreasing by the allowable depletion amount rather than the water applied during irrigation?? Is that correct or am I missing the boat on this? Thank you and appreciate some input.

[Michel Kohanim]

Hello strahan001,

 

Allowable depletion is a function of water applied per irrigation cycle.

Allowable Depletion = Water Applied Per Irrigation Cycle * Absorption Factor.

 

So, if absorption factor is close to 1, then those values shall be identical.

 

With kind regards,

Michel

[strahan001]

Ah ha! Thank you!!

[strahan001]

So I think I have this irrigation thing finally figured out, the hardest part is trying to figure out the absorption factor. I am now to a point that I would like to have the system e mail me when they system is watering, along with that e mail it will simply poll the weather bug information and provide a nice little report for me to see what the information was for the day. For some reason when I have put this option in the program the ISY spams the heck out of me and I can't seem to figure out why. Does anyone have any type of similar issue? Or seen this before?

[Nuttycomputer]

So I think I have this irrigation thing finally figured out, the hardest part is trying to figure out the absorption factor...

 

I'm having the same difficulty. After getting the EZFlora and a sprinkler leak fixed I was ready to get my program running and saving me water. However the absorption factor is where I'm stuck. From what I understand earlier in the post it was stated that the irrigation requirement was lowered by the Allowable Depletion... However when I set my soil type to the listed name of Clay it shows that as under an absorption rate of 17% and a very small Allowable Depletion number. If I used the program in this manner I would be watering far more often then I should.

 

I'm struggling with this because that doesn't make sense unless the labels were inadvertently placed backwards. My understanding is clay is supposed to have a far superior water storage capacity and therefore I should be watering less. Is my thinking wrong or is the module using different terms than I am?

[LeeG]

Clay is one of the worst soils to water. It absorbs water very slowly compared to other soil types. I am not familiar with the Irrigation module but do live where clay is prevalent. Often necessary to break watering cycles into multiple short cycles to avoid water just running off clay.

[Nuttycomputer]

Clay is one of the worst soils to water. It absorbs water very slowly compared to other soil types. I am not familiar with the Irrigation module but do live where clay is prevalent. Often necessary to break watering cycles into multiple short cycles to avoid water just running off clay.

 

The nice thing about the ISY is I can do the short cycles and wait. This is no problem. However once it actually gets into the clay it should also stay moist and be providing water at the root level for far longer then other soil types such as sand that will just drain straight through. At least that is my understanding.

 

Is the absorption factor in this case factoring in runoff as if I watered the system in one long cycle with no break? If so then it would make sense why numbers are so low...

[Michel Kohanim]

Hi Nuttycomputer,

 

I am not sure if you have time (or the desire) to read the history behind our Irrigation Module. If you do, it may shed some light on why we did what we did:

viewtopic.php?f=7&t=6452&hilit=absorption+factor

 

Absorption factor is a heuristic number which Evapotranspiration algorithm takes into consideration based on other variables such as temperature, humidity, pressure, etc. Here's some high level background on Evapotranspiration:

http://www.universal-devices.com/mwiki/ ... Irrigation

 

With kind regards,

[Nuttycomputer]

Hi Nuttycomputer,

 

I am not sure if you have time (or the desire) to read the history behind our Irrigation Module. If you do, it may shed some light on why we did what we did:

viewtopic.php?f=7&t=6452&hilit=absorption+factor

 

Absorption factor is a heuristic number which Evapotranspiration algorithm takes into consideration based on other variables such as temperature, humidity, pressure, etc. Here's some high level background on Evapotranspiration:

http://www.universal-devices.com/mwiki/ ... Irrigation

 

With kind regards,

 

Michel,

I did attempt to read the history and have read as much as I can on the ideas behind evapotranspiration. I admit a lot of it is presently beyond me. However, I guess I'm confused because in my previous program I would put down about an inch of water a week. Putting out that water slowly so that it would get absorbed into the mostly clay soil.

 

Where I'm getting confused though is everything so far that I've read regarding the evapotranspiration indicates the clay has a higher water storage capacity then any other soil and consequently will provide for the grass longer with less watering (as long as you make sure to water intermittently as to avoid runoff) However if I set my irrigation system up to deliver .5 inches of water a run and set it to Clay the last few days I've been monitoring the irrigation module would have me watering every day because the Allowable Depletion is .085 but we've lost average this week .15 inches a day... That surely can't be right can it.. not in the spring?

 

Perhaps I'm doing something else fundamentally wrong? I will re-review that forum and see if I can locate the problem.

 

Thanks again for the continued responses to my questions throughout the forum as I ramp up my system.

[strahan001]

Any comments regarding the spam of emails that the ISY produces when I place it at the end of the irrigation cycle?

[Michel Kohanim]

Hello strahan001,

 

Please copy/paste your program here ...

 

With kind regards,

Michel

[Michel Kohanim]

Hello Nuttycomputer,

 

Allowable Depletion is the amount of water that's depleted from your soil based on the absorption factor and amount water applied:

Allowable Depletion = Absorption Factor (

 

So, are you referring to Allowable Depletion OR Irrigation Requirement? Allowable Depletion is constant while Irrigation Requirement is calculated based on Evapotranspiration which does take into account Allowable Depletion.

 

With kind regards,

Michel

[Nuttycomputer]

EDIT:

 

Michel,

 

I got a chance to read those 19 pages again and I see what went wrong and I stand behind the problem I'm reporting. Perhaps it was because I got to read it all in one sitting as an observer instead of trying to participate. Absorption Factor / Soil Type is indeed what I hypothesized it might have been in the original post that follows. It was added to ensure that Rain was correctly accounted for. The problem is it is a rate, that is how much water the soil can absorb over a period of time, in this case hours) which is suitable for being applied to rain because ISY measures rainfall and rain rate. For example if I receive 5 inches of rain within an hour and my soil absorption rate is 2 inches an hour (or 20%) then 3 inches is lost to runoff and so assuming it stops raining for the rest of the day then only the 2 inches should be removed from the irrigation requirement.

 

The Core of the problem however arose around page 15 where it was included, unexpectedly based on previous discussions, into the calculation of Water Applied per Irrigation. Then it was suggested, incorrectly in my opinion, to rename it to Allowable Depletion. The problem isn't the name, which I admit is confusing and incorrect, it is that soil absorption was added into the Water Applied per Irrigation in the first place.

 

The problem is that Soil Absorption is a Rate that can't simply be added to Water Applied per Irrigation unless you know not only how much water was applied but for how long it took to apply that water. For that you would need to have the user input station run times and calculate it for each station. That is far more work on your part than I think is necessary. I think it is better to leave it up to the user to tell you how much water was added to the soil when they ran their system.

 

Even then it still isn't allowable depletion which is based on the factors I listed below and were correctly discussed until page 15.

 

Michel, In addition would it better to move this entire post over to the original discussion?

 

----- ORIGINAL POST -----

 

Hello Nuttycomputer,

 

Allowable Depletion is the amount of water that's depleted from your soil based on the absorption factor and amount water applied:

Allowable Depletion = Absorption Factor (<=1) * Water applied per cycle

 

So, are you referring to Allowable Depletion OR Irrigation Requirement? Allowable Depletion is constant while Irrigation Requirement is calculated based on Evapotranspiration which does take into account Allowable Depletion.

 

With kind regards,

Michel

 

Sigh - I wrote out a nice several paragraph response when my browser decided to crash lol. I guess the confusion Michel is that the Allowable Depletion and why it is multiplied by the absorption factor and water applied per a cycle is not matching with what I've read it should be.

 

Allowable Depletion from my understanding of multiple sources including the wiki you posted above ( http://www.universal-devices.com/mwiki/ ... Irrigation ) is the amount of water that can be lost from the Available Water before the crop/plant/grass has problems with water stress.

 

You are correct this is a set constant amount but it shouldn't have anything to do with how much water I'm putting into the system or absorption factor (I admit I couldn't find this term in any of my reading)

 

On a high level, and some websites out there will walk you through it, these are the factors I understand should be at play when deciding if/when to water:

 

Allowable Depletion: Again, how much water could be lost from the soil before the plants are water stressed. This is a product of the Max Available Water and a Percentage Factor based on type of plant. (For simplicity they recommend using 50% for cool grasses, such as mine, but you could taylor it to specific crop/plant)

Max Available Water: Product of Soil Water Storage Capacity and Root Depth. This is what is actually available to the plants.

Soil Water Storage Capacity: This is where Clay shines. Though clay takes longer to reach this point, shorter but more irrigation cycles, it holds more moisture. I've seen estimates listing 2.0 in/ft to 2.5 in/ft capacity

Root Depth: Self Explanatory

ET: Water loss from soil through evaporation and transpiration. I won't get into the math behind this. I barely understand most of it and I have no doubt the program does this part very well.

Water Defifcit / Irrigation Requirement: Max Available Water - ET

 

Goal: Run Irrigation Cycle when the ET causes the water deficit to reach the Allowable Depletion Threshold.

 

- To use an analogy. Max available water is how much gas my car tank can hold, allowable depletion is the point my light comes on, and ET is my gas mileage.

 

This is how I understand how this should work and matches the diagram. So to through some numbers in here.

 

Water Storage Capacity - I'll use 2.0 in/ft for clay. It's on the lower conservative side though I could do an experiment to actually test this for my specific soil and maybe someday I will.

Root Depth - I actually have about 3 different grasses that grow in my yard due to the temperature swings of my area. For simplicity though we'll use the cool Kentucky Blue Grass that has started greening. Local College has done this work for me and says they grow a root depth of anywhere from 8 inches to 14 inches for my area. I'll use a simple 10 inches. It's on the lower side and I don't feel like digging it up to see what the actual root depth is right now

Max Available Water ~ 1.6 inches. Any percipitation/irrigation put into the soil beyond this point is useless to the grass and is the equivelant of letting the gas just spill out of the tank.

Allowable Depletion: .80 inches using the simple 50% for cool grasses

ET: The controller does this work for me but to make it simple I'll take the value of yesterday which was .13 (cool spring day)

 

If I assume for simplicity sake the ET is constant and reset the system such that is assumes I have a full tank of water it should call for water in about 7 days. I can then setup my program to add the full .8 back or do a partial and just add .5 inches back in assuming the spring rains we have around here will probably make up the difference in the next few days. This historically matches my experience with watering in the spring.

 

 

So the problem I'm having with my understanding of how the controller works is if I tell it I'm going to put in .8 inches of water it calculates an Allowable Depletion of .136 using %17 clay. It is the .136 number that is subtracted from the Irrigation Requirement. This means given the ET above the system would be calling for water (.8 inches of it) nearly every day. In the summer I would never be able to make up deficit represented even though I would be putting down 7 inches of water a week. In the meantime it would drown my lawn.

 

 

So I guess given the above am I missing something simple, are the terms being used different? Going back to how Allowable Depletion is calculated as the program understands it: Allowable Depletion = Absorption Factor (<=1) * Water applied per cycle. That actually sounds like it's trying to determine absorption rate except missing the time factor of the cycle. This would make more sense as yes Clay is horrible at actually absorbing the water. Mine can only absorb probably about .2 inches an hour. Which is why I water using multiple short cycles. But this is all done on my end.