Rookie420

@Njanne, if your lights don't have a dimmer option I recommend getting a plug that you can manage the Watt output from. You can get a duel pack dirt cheap and they work great that will dim your lights so they aren't too intense

The issue with the leaves are one of 2 things, 1. Light too close 2. Not enough calmag in your mix as using coco u need that bit extra as tho coco loves to absorb calmag Boost your humidity too to the 50-60 mark, the damaged leaves won't go back to a healthy colour it's the new growth you want to be looking at, try using 10ml of calmag per 10L

With the issues you keep getting and with you using mainly Coco in your mix I recommend flushing the plants for a few days at a PH level of 5.8 - 6 When you do start to give them food give the medium a very light watering with Just PH water and calmag before you give them there food, COCO tends to steal the calmag not leaving enough for the plants to take so by dampening the water with a cal mag feed first allows your plant to get the full dose from your feed. (Its hard for them to Overdose on Calmag so your safe) You say your using strips to test Ph I recommend getting yourself a soil and water PH meter, you can pick a pack that contains both from amazon for arround £25. Try adding some Co2 into the room and my checking drainage holes are big enough that may also help + with you running LED try bump up the Temps to arround 26-28°C as they dont produce slot of heat and you want the leaf surface area to be arround 24°C other than that it looks great

Planning to flip in 3 week

Grow 'em all!!!😁👽

Good luck with the grow mate! 🌱😎

Good Luck! @Rookie420

Try increasing your humidity as it looks to be heat stress that is causing the curl the plants can't get the moisture they need at 45%