Fan Leaves curling up

Not sure if its genetics or what but my Platinum OG fan leaves are curling up. It seems only the Platinum OG is having this issue otherwise everything is fine. More so curious than anything because the growth seems fine. Any help would be appreciated.


Hydro - Ebb & Gro
PH - 5.6 - 6.0
Medium - Grow Chunks
Temp @ 74 F
Humidity @ 65%

Update

Increased the humidity and the problem went away.

That is called canoeing and it is a signal of heat stress. Often a combination of too close a light, low airflow, to high a temp and low humidity.
I would say you should look at something other then the humidity as 65% is to high and will promote MOLD.

I appreciate the input. I raised the humidity to 70% and everything in the room loved it as growth sped up. I didn't want to change too much because everything else was doing just fine. I'm still running 18/6 right now so I wasn't concerned with mold. I appreciate the heads up though and will most definitely lower before the fruit start producing. Where did the like button go?