Cheers for all the positive comments guys.
method so far was 1.5 litre square pots, at two weeks from sprout all sexed and potted up into 18 litre capacity (but not full poly pots )
so far they have had plain well water but they did receive a sprinkling of 'black pearl' under the roots on transplant , and then a week later I gave a dressing of worm castings.
they don't require that frequent watering in those size containers at the moment, but next watering in 3-4 days I will give them some liquid organic nutrients from the barrel .
Cheers mitch