Date: Wed, 4 Mar 1998 16:05:36 +0000 From: Stuart Haxton <stuart@haxton.demon.co.uk> To: cp@opus.hpl.hp.com Message-Id: <aabcdefg847$foo@default> Subject: auto irrigation system!
Hello all,
During a visit to a garden centre, I saw an irrigation system on
display which waters your greenhouse plants automatically, whenever you
want, without any kind of supervision, by means of drip heads and/or
capillary matting.(it only uses gravity as power and therefore will not
supply the pressure for misting). I saw that this could be adapted to
filling trays, watering pots or damping a greenhouse floor (something
that can be very tedious if you have to do it all the time.) The system
cost 59.95. Ridiculous, because all it really consisted of was a tank
and a simple system of tubing.
I will attempt to explain it, as I went home and managed to construct
exacty the same system and it cost me nothing more than the following
materials;
1 old _plastic_ oil can with hollow handle (or similar) washed.
At least 1m of flexible plastic tubing, with a bore of no more than 6mm.
Any kind of sealant for plastics.
Around 30 cm of very thick wire, bent into an 's' hook shape.
A funnel.
That's it.
Here's the instructions;
1. Cut away the top section of the can to leave the main 'bucket' part,
leaving the handle intact, and also a flap higher than the rest of the
rim.
2. Bore a hole in the base of the can of the same diameter as your
tubing.
3. Feed the tubing through the hole so that it projects around 30 cm
below the base. (this provides the gravity for a good flow.)
4. bend the tubing over (no kinking please) and feed it down the handle
of the can until it reaches the base. The apex of the curve in the tube
_must_ be below the rim of the can.
5. Seal the tube to the can where it goes through the hole in the base
to stop leaks.
6. Now drill a hole in the flap you left in the rim. Hang the tank at
the highest point possible in your greenhouse, at least 1m higher than
the plants you want watered, or the greenhouse floor (if you require
damping-down)
7. Using a regular garden horse, bring water into the greenhouse, from a
header tank of rainwater (high enough above the siphon tank to allow
water to run from one to the other) or the mains, or even a R.O. unit if
you are actually watering the plants, (especially Nepenthes). Using a
tap or a valve from one of these sources adjust the flow so that water
merely trickles into the siphon tank.
8. Just below the downpipe from the siphon tank, fix the funnel to the
greenhouse wall, connected to another tube which will carry away the
water to whatever you want it for.
9. ADJUSTING THE TIMING
If you want your greenhouse to be damped down, say, every hour, simply
adjust the amount of water going into the tank so that it takes 1hr to
reach the level of the bend in the tube. Then, like magic, the siphon
will be activated by gravity, and water will begin flowing at surprising
speed from the tank.
10. ADJUSTING THE AMOUNT
Obviously if you use a 10 gallon drum for a 6x4 greenhouse you will have
a flood of biblical proportions every hour. Therefore choose a tank that
suits your needs. If you want to regulate the amount really accurately,
measure the amount of water the tank takes, say 2 pints. If you only
want it to give your plants 1 pint, (eg. if it's winter and you want
less watering), get hold of a 1 pt bottle, fill it with water and put it
in the tank. This means that less water will go through the siphon.
This will result in more frequent waterings, due to the faster
filling rate. Simply reduce the supply rate by the right amount.
You can fix up quite a complicated network of watering tubes all round
your greenhouse...or windowboxes...or flowerbeds...
--------
That's all.
If all that sounded a little confusing, I've drawn a diagram of it in
grayscale .BMP and I can mail it to anyone who's interested.
All of this costs around 5 to build... a saving of hmmmmm...54.95!
D'ye think it's worth it?
-- Stuart Haxton
This archive was generated by hypermail 2b30 : Tue Jan 02 2001 - 17:31:29 PST