In article , Janice
writes
Hi I'm not sure if I can explain this properly but here goes.

I want to add a liquid fertilizer to my automatic watering system in my
greenhouse which is fed by a Gardena electronic timer. Basically I want to
convert the whole system to hydroponics but I need a way to add the nutrient
to the water flowing in the hosepipe without the nutrient running out when
the water is stopped.

What I need is for a tank of nutrient to be mixed in with the water but not
for the water to flow through the tank and mix it all in at once so that I
can leave the whole thing for a couple of weeks when I go on holiday so that
everytime the water flows a measured amount of nutrient is added to the
water.

Is such a thing possible or will I have to get a pump and a large tank and
pump the water and nutrient around in a closed system? The problem with
that is if the pump fails the tomatoes die.
This is all for next year as I want to try a different method of growing
tomatoes so that it is all automated and I want to try to grow things
hydroponically and not have to rely upon unreliable neighbours.

Hope you understand all this

Try:
http://www.lbsgardendirect.co.uk/cat...at_id=DILUTORS
The hanging basket version might suit you. Watch out as the others are
designed for higher flows and just won't lift the feed if you run them at low
flows. They do a 10% introductory discount.

Note however that they don't seem to be advised for long slow delivery, the
notes on that page suggest a short feed cycle then water alone then refill
and feed again.

http://www.access-irrigation.net/index.htm are the makers who do sell as
well but may not always have stock, useful info on site.
--
fred
Plusnet - I hope you like vanilla