hiya, thanx,
right she is using a flood and drain system.
started from seeds
in rockwool cubes in clay pebbles
not sure of age exactly but has only just put into system so are about 4-6 inches.

i know using mine (conductivity meter i think)i tend to go 12 during vegative growth rising to 20-24 during flowering so if a comparable idea would be good.
Am going to fone her and tell her to keep it betwen 200 and 400 for now then and to go up to 1300 - 1400 when flowering .
does that sound about right.
will also give her your tips about checking for brown, curls or too dark a green.
Any more help as gratefuly recieved as this