i forgot to give details

Light : 400w MH
medium: rockwool in hyrdoton rocks in a hydro system
PH:6.8
Humitiyu: 38%
age:3.5 weeks
(nutes) i think i have been to careless i gave my plants a full dose of nutes bc thel eafes were yellow and i thought that meant nitrogen deficioncy and the half dose wasnt making it greener