Day 28 Plants With Leaves Curling Up

[Billybud50]

I am on day 28 of flower. I have 20 skywalker strain plants and 6 Black Eyes Katy in 15 gallon pots. Medium is Royal Gold Tupur(coco perlite mix) Running advanced nutrients connoisseur line at 75% strength. Currently feeding 15 gallons 2 times per day. Everytjing has looked great but I noticed a few of the skywalkers have curling leaves on top. Any idea why?

 

[Thejoeybrown]

Have you scoped them? I know everyone always jumps to that but it’s always good to eliminate the possibility of russet/broad mites. The shiny waxy look on the leaves in the bottom pic make me wonder.
Post up all your info
Temps (day/night)
Rh
Ec/ppm
Ph

 

[CaliRooted]

What's the temperature in there?

 

[StandingRock]

Humidity is too low/vpd is incorrect.

 

[StandingRock]

I would also say light stress or leaves are getting too hot.

 

[Leew421]

Looks hot. Not a good light arrangements. You could be running less light to get all that

 

[Junk]

I agree with @StandingRock , with the addition of the feed being a little hot. It looks dry in there, and the plants look a tad overfed.