Posted: 19/03/2014 at 18:38
When I lived in a truck, I had a foot pump attached to a 5 gallon water container and I could pump water into the little sink via a tap. I got all this equipment from a caravan supplier, but it was 42 years ago But this technology is bound to still be around.
I assume the roots of the plants are several metres up in the air? Perhaps some pics would help us to advise you.