I was thinking it could be overfeeding i use advanced nutrients and since i noticed this i used water. Its my 4th or 5th grow in this setup first time this happened and always temperatures in the 27-25° cNo something is off a little. I'll throw out cal-phosphorus deficiency, the leaves are getting chlorotic and flagging.
Any pH checks or temp and RH% in tent.
I will try, on my first runs that didnt happened but last one i had to buy cal mag but the signs were much more advanced i will try adding in the water i believe its the best choice, thanks for the helpIf you in coco with LED and you dont add cal mag 1ml per liter every feeding it does that ..my personal experience and i stopped using coco went back to peat moss and never stopped giving that 1 ml/liter cal mag every feed they love it !
also when they look sad like yours id say foliar spray them with a 1ml/liter calmag + declorinated water room temp 2 times per day, dim the light down tho, to not burn them , and watch them thrive after a couple of days.( with coco 1.5ml to 2ml per litre would probly be even better since coco breaks down calicium.
My 2 cent.