perlite/vermiculite? Before flowering plants throw off a lot of leaves especially outdoor (out of experience) and remember leaves can't repair themselves. So damaged leaves whether it be from nutrient burn / pests would stay until the leave falls off. leave discoloration due to nutrient deficiency can be fixed though. Elder weed growers are welcome to correct any of the above.
looks like heat stress with over feeding or nutrient lockout. Posting a pic of the whole plant would help also medium? and what nutrients are you feeding? and finally how often do you water?
Hopefully prices will drop ,paying 160 a gram is no joke! I have 12 babies outside. 2 are coco/perlite/wormcastings rest are soil. I'm just worried about the rain destroying my coco babies. also my plants show no sigh of pre flower ? CPT