
Autonomous Plant Watering - ashitlerferad
http://blog.monotonous.org/2016/05/25/autonomous-plant-watering/
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foxhop
[http://www.richsoil.com/hugelkultur/](http://www.richsoil.com/hugelkultur/) |
hugelkultur is real autonomous plant watering - I have built 4 of them on my
.35 acre property.

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mod
Hey, I've got one half-built! I was building mine in a line/row and trying to
get it as tall as possible, but I could only reasonably get it to about 4
feet. I imagine it'll settle to ~2 feet in the end. It's about 3 feet wide at
the base and about 45 feet long, mostly awaiting me to mound the dirt up.

I haven't decided what to plant it with, though.

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foxhop
Yeah, one of them that I built is hollow inside due to using lots of sticks
and branches instead of logs, I assume it will settle in time and shrink
considerably.

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mabbo
I built my own little system yesterday that use no electricity.

An upsidedown 2L bottle sits above a reservoir and if the water gets too low
it glubs out some more water. Air gets in, water comes out, now more air can't
get in because the reservoir water is too high.

A set of aquarium tubes keeps the water level even between the reservoir and
each plant. The plants are all in double planters, with water in the bottom
one. Clothes strips wick the water up throughout the soil in the top planters,
keeping the soil constantly moist.

It's been less than a day, so we'll see how it goes but the whole thing was
cheap and simple.

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cornchips
Plants will die without air to the soil/roots. Many plants require wet/dry
cycles.

You should start seeing fungus gnats in a week or so.

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mabbo
Hrm. Interesting.

I based this system off a large number of videos showing the double-bucket
wicking system. Folks in those said they had lots of success using them. Does
that only affect certain plant types?

Edit: some material I found suggests that because the surface soil stays dry,
the fungus gnats have a hard time getting into the roots, propagating.

[http://www.insideurbangreen.org/2010/07/subirrigated-
planter...](http://www.insideurbangreen.org/2010/07/subirrigated-planters-no-
more-fungus-gnats-.html)

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cornchips
As the plant kingdom is diverse, there is no yes/no. Though you can say this
is a general problem in common soil. You can imagine jungle/pond plants are
more tolerant of wetness, but not of the possible pests... The ecosystem of
any given soil is quite complex [0]; the environment, symbiotics, pests and
predators keep things in balance.

0 [http://www.osoils.com/wp-content/uploads/compost-
tea-41.jpg](http://www.osoils.com/wp-content/uploads/compost-tea-41.jpg)

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05
Or just use a $2 Arduino clone, a 12V pump and a 50¢ TTL MOSFET.. And you'll
even be able to add soil moisture sensors to compensate for external factors
like air temperature/humidity

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franciscop
That's exactly the point, he got a reliable system with off the shelf
components that is more reliable than your proposed solution (no water =
burned pump, can mix anythig in the water, etc)

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mrfusion
Could you have a single one outlet pump but then have four tubes coming out of
the jar going to different plants?

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pierrec
Sounds like a good pipe network analysis PhD subject.

[https://en.wikipedia.org/wiki/Pipe_network_analysis](https://en.wikipedia.org/wiki/Pipe_network_analysis)

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llbit_se
Nice little setup. Here is my watering system:
[http://llbit.se/?p=2827](http://llbit.se/?p=2827)

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teslabox
I'm thinking about something like this, thanks for posting your link.

My father's house has a greywater septic system. The treated water is sprayed
on an "orchard". The trees don't get watered when people aren't in the house,
so most the trees are gone. I'm going to plant raspberries. :)

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nihakue
The Wifi outlet seems like mega overkill to run a schedule. Couldn't you just
use one of these?
[https://www.google.co.uk/search?q=socket+timer+us&safe=off&b...](https://www.google.co.uk/search?q=socket+timer+us&safe=off&biw=1440&bih=778&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjFzZLfgP7MAhUmC8AKHbVyAKQQ_AUIBygC#imgrc=bIMMDcBcN3CWoM%3A)

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joshstrange
Those normally work in 30min increments minimum, this stays on for 20 seconds,
once a week. I already own a "smart outlet" so the cost for me would be less
than $10 to build this, I just got into growing herbs and this would be a
really awesome setup.

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nkurz
In case it helps anyone, there's a well-documented hack for modifying one of
the more common types of rotary timers to allow much shorter increments:
[http://hackaday.com/2011/09/09/repeat-timer-hacked-
for-35-mi...](http://hackaday.com/2011/09/09/repeat-timer-hacked-
for-35-minute-hydroponic-cycles/)

This wouldn't work if you want 1 minute a week (since the cycle repeats every
35 minutes), but for hydroponics sometimes you want a short duration with very
frequent repetitions, and the electronic timers (which are preferable in most
other ways) don't provide enough on/off cycles per day or week.

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fovc
I wonder if you could chain two timers, picking their periods and durations
appropriately to get a much longer combined period with the correct duration.

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heffo
Well, you could use 2 timers with the same period, if they are accurate.

You would plug in timer 1, so that its output (output 1) is on. You would set
timer 2 so that output 2 would turn on as soon as timer 2 receives power. When
there are only 30 seconds left in timer 1's on cycle, you would plug timer 2
into a separate outlet.

Since they are synced, but only overlap by 30 seconds, they will only both be
on for 30 seconds. You would then need some kind of AND that would only turn
on the pump if output 2 and output 1 are both on.

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thrownaway1984
Plugging one into the other would provide an AND.

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quesera
The second in series would not be powered continuously, so it would only work
for the first cycle.

You'd need to separate the timer power from the switched power. Easy to do,
but not how the cheap ones work.

Also, the settings are not precise enough to get a repeatable interval across
two devices.

On the other hand, it's a very simple DIY electronics project. Arduino is
extreme overkill, but will also work.

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TheMagician0
"I really don’t understand the physics that makes that system work, but it has
a lot to do with water pressure..."

For those who are curious: In simple terms, pressure is proportional to depth.
Assuming the air pump is outputting constant pressure, the pressure exerting
on the top surface of the water would be constant. On the other hand, the
amount of pressure experienced at a point near the bottom of the container
depends on the its depth- the deeper the more pressure.

When there is more fluid, there is more pressure near the bottom due to the
weight of the fluid itself, which allows greater output (water going into the
soil). As the fluid's depth decreases, so will the pressure experienced by a
point near the bottom.

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js8
My mother always recommended to use a string, which will soak up the water and
lead it to the plant.

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EGreg
So we have computers watering plants, and maybe feeding animals etc.

And that kind of makes me think we are implementing some sort of new,
unnatural ecosystem where energy is expended by robots. But will it be self
sufficient and sustainable?

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JshWright
I don't understand the reasoning behind the overly complicated air pumping
setup. Why not just use a small submersible aquarium pump?

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scott_hardy
These reasons are (casually) mentioned in the post:

* "the deeper your reservoir the more efficient the water gets pumped. As the water gets consumed, the pump gives less output"

* "If the reservoir runs dry the motor won’t catch fire. That apparently is a thing water pumps."

* "Since the water is only going through a simple tube and not an expensive motor, you can pump a nutrient solution. If you want to pamper your plants, we don’t."

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JshWright
An impeller driven pump moves a fixed amount of water per revolution.

There are very few pumps on the market nowadays (even the super cheap ones)
that don't have run-dry protection. In any case, no pump is going to catch
fire running for 20 seconds.

It is very common to add fertilizer to planted aquariums. It's dissolved in
the water, and therefore makes no difference to the pump (it doesn't change
the "pumping" properties of the water at all).

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noonespecial
This looks like a job for a peristaltic pump. They can be had on ebay for a
few $ and would allow very precise watering amounts.

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morcheeba
not that precise ... as the tubes age, prepare for 50% less volume per
revolution than a new tube.

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choperius
Worked on a similar concept during a hackathon. You could potentially connect
plant watering to a system like Nest/Toon and get data from all your plants -
track temperature, soil moisture, water and energy spending.

[http://telegarden.xyz](http://telegarden.xyz)

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atomical
"Watering the plant would be too easy, we need a technological solution that
will hydrate the plant and not require us to change our comfortable habit of
neglect."

Sounds like the typical eureka moment.

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Tharkun
I agree. Plant watering really doesn't require any kind of electrical
solution. There are oodles of self watering planters which rely on a reservoir
and gravity.

But for the HNers with a slightly greener thumb: I have a big sanseviera which
I use as a kind of alarm clock. Whenever it gets droopy, I know it's time to
water all my plants. And because it's a big and hardy plant, it prevents me
from overwatering my other plants.

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Bromskloss
> There are oodles of self watering planters which rely on a reservoir and
> gravity.

Do you have any recommendations?

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agumonkey
I ran into an idiom last month. Something like food computing. A trendy name
for everything about home automation regarding growing vegetables. Anybody can
confirm ?

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vatotemking
Does anyone know of a good windmill pump schematic?

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cody3222
In the real world we call this rain

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gravypod
I don't think I need to tell anyone that running any pump dry, unless it's
sold to do so, is a bad idea.

Why didn't they pump the water from the tank to the plants? Why did they rely
on pressure? That puts a whole lot of strain on the pump.

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rcarmo
That's actually explained in the article. Plus it's an air pump...

