hi,,, i wold say its acombination ....
but at first i would blame the lightdistance.
the Viparsectra XS-1000 is a powerul light ( iam having it too... and i burned twice my plants)
and that is how they look if they get burned. those yellow leaves are the product.....
and you mmight look for an ec of 1200, and uusing the calmag product of your chice, that will help herin the photosynthesis
but remeber, most calmag products contain nitrogen too........ so mix the nutes, get the ec and feed them
The drooyness let me feel like the roots having a problem with oxygen uptake
i will let you a link for dwc growing
you can look into my diary of the CBD white widow,,,, there you see the difference before i burt the plant and afer, ive let her only 2 days under the light
and after this i dimmed back and put my seedlings under the light,and burned them too...loool atm
i dimmed back to 50 percent and the small plants have asdistance o 65 cm... the bigger plants are closer because of the growingpot---- looks for the viparspectra diaries,, cheers