On Sunday, 8 May 2016 09:16:05 UTC+1, MM wrote:
On Sun, 8 May 2016 00:00:59 +0100 (GMT+01:00), Chris French
wrote:

MM Wrote in message:
I'm trying to set up a home-brew drip feed irrigation kit for 6 tomato
plants. I've already got a lot of suitable tubing, the T-pieces,
connectors, drippers etc. The water feed is off a new 230 litre water
butt to which I have attached a brass tap instead of the black plastic
one. To the tap I've connected a Hozelock electronic water timer
(AC1), which Hozelock customer services confirmed will work with a
water butt, and it does.

So I placed the tomato plant pots close to each other and close also
to the water butt, then ran the tubing from one to the next. I then
switched the AC1 to "always on" for testing.

The problem is that even when the butt is brimful it seems to have
only enough head of water to feed three of the drippers. And even then
the third dripper furthest away from the butt dribbles rather than
drips. The water will just not flow around the circuit to all 6
drippers, and I can't understand why not! I even tried sucking on the
little pieces of tube as if to "bleed" them of air. No improvement.

The feed to the first 2 pots is excellent and the water drips really
nicely. So it would work for 2 plants, possibly 3. But where am I
going wrong? The water butt is mounted on the typical black plastic
stand, which is about a foot off the ground.


I'm asking as it's not clear from the other answers. What pipe
arrangement have you got?

Is there one larger pipe (12mm) from the timer feeding separate
pipes and drippers with via the smaller 4mm pipes?

Yes. The setup is as follows: When I bought the original drip feed
irrigation kit from QD for about £3.99 a couple of years ago it
included an adapter for a bib tab. Now I can't find the adapter
anywhere. I've got roughly 23m of 4mm black tubing, umpteen drippers,
connectors and T-pieces, but no adapter. You can get them on the
internet easy-peasy, but I'm going on holiday so I needed a solution.

So I bought three short lengths of clear plastic tubing of reducing
diameters and stuck one inside the other (tight fit in all cases)..
Then I screwed a standard hose connector on to the outlet on the
Hozelock timer and pushed the largest of the plastic tubing over the
spigot (where you'd normally connect the garden hose or sprinkler). So
the line-up is:

Timer - hose connector - clear plastic tubing large - clear plastic
tubing medium - clear plastic tubing small - black 4mm tubing -
drippers. The clear plastic tubing *in total* is approximately 17cm in
length. The black 4mm tubing is about a meter, as I've got all the
pots in a cluster. The pots are about 30cm dia at the top and about
35cm high. The top of the pots is level with the tap on the butt.
There is 230 litres in the full water butt.

When I remove the black tubing from the smallest clear tubing and
switch on the timer manually, water gushes nicely from the clear tube.

When I reconnect the black tubing, water still flows nicely, but
doesn't gush. It's only a 4mm tube, after all!

The water then reaches three drippers, but the fourth barely dribbles.
Five and six, well, you can forget about them, they never even
dribble!

I'm assuming that the minimal pressure this latch-up is under is
exhausted by the time the water gets to dripper number 3 and isn't
sufficient to push the water along another foot to pot #4.

My stop-gap solution right now: Use the water butt for the three best
plants and take the remaining three to my brother's where he or the
missus can water them for me.

For my next experiment (!) I shall (a) look at acquiring or making a
tray for the wicking method and (b) try using a length of small-bore
copper tubing instead of the black plastic, which is really crap to
work with. For "drippers", drill small holes in the copper tube. But
no time to do that now. I haven't a clue where to obtain such copper
tubing anyway.

MM

If you want a quick dip tray, just use polythene propped round the edges for the tray & cardboard for the mat.


NT