Is this Nutrient Burn ? I thought it might have been the light but pretty confident it isnt due to the lower leaves being affected. Ive started a flush. Do you think it's gone too far ? Are they doomed ?
It is both.
The bunt tips = nute burn
The yellowing and small amounts of purple by the damaged area are signs of light damage.
Also, check your PH meter. You may have lockout
Yeah I would say slight nute burn, they will be fine, flush with p/h’d water till your run off ppm has dropped right down then resume feeding at half strength and dial your ppm in from there