wrote:
On 29 Jul, 22:44, "Janice" wrote:

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

Thanks Jan

this sort of kit has been common in commercial nurseries for decades.
ISTR a Cameron diluter. Probably available in plastic for home use by
now.

They were deemed a safety risk due to back syphonage, so ensure a
double check valve is used with one.

The water authorities consider everything to be a safety risk due to back
syphonage. Some don't consider a NWC approved double check valve sufficient
protection.


--
Dave
The Medway Handyman
www.medwayhandyman.co.uk
01634 717930
07850 597257