Day 35 flower, thoughts on leaves curling at edges ?

[78OzFinest]

hey all, im 35 days into flower and some of the leaves on my tops are starting to curl up around the edges, they are still green and healthy looking aside from that. what do you think the most likely culprit in this case would be ? heat stress? ive checked on them a few times and the temps have been up around 34 degrees celsius for a little while before i noticed and corrected their average temp during lights on is around 28 probably. perhaps nutrient related ? or the lights being too close ? ive read through various posts on the subject , but i was hoping perhaps someone on here could pinpoint the issue with a picture. any advice is greatly appreciated :)

 

[Mr.Juice]

Looks like taco-ing due to heat stress. I am by no means any expert. Hold the back of your hand at the level where they are curling for a minute.

 

[Dirtbag]

Yep, heat. If you have a laser thermometer check the leaf temp. What kind of light and how close is it?

 

[78OzFinest]

okay, im gonna raise the lights up haha, theyre 250w quantum boards, just checked and the closest top on the affected plant was 12 inches.. i raised it up 4 inches. hopefully that is enough, i cant raise them anymore on my ratchet hangers now, if this is not enough ill have to lose them maybe and find another way to string them up. i had a temp gun but took it back after i checked my drivers and leaves lol... the hottest leaves at the time were around 27, but theyve since grown up closer to the lights. my tallest girl however is just as close and none of her leaves are showing the same symptoms.. the temps lately have been getting cooler so i should not have anymore surprise 34 degree moments in the tent haha, perhaps thats when she decided to taco up a bit haha.. guess i will see how she rreacts to the lights being raised a bit and go from there!

 

[Dirtbag]

I'm not an LED expert by any means but I've read a few times that 18" is about as low as you want to go. From the look of the leaves given the room temp isnt too high at the moment, I'd think it's a safe bet to say the light is probably too close.

 

[78OzFinest]

backing it off on the lights! thanks for the help man, cheers. cant wait to see how much weight these girls put on in the next 3 weeks! first harvest is going to be pretty exciting haha, big weight no whammies lol