leaves that curl down

Hi. Can anyone please tell me why the leaves of my w widow is curling down. Please see pics attached and let me know what you think. Ph is between 6 & 7, temps around 80, plant about 5 weeks old under veggie lights for 18 hrs a day.
Any help?

it looks like the stalk is a little stretched and the leaves aren't getting enough light. what type of light do you use and how close do you keep it to the plant?

kinda looks like nitro deff.....

Lights are kept about 3 inches from plant, for vegg I'm using 2 four foot flourecent 56k bulbs. Right now I'm not feeding since I'm jusing miracle grow moisture control with fertilizer.
Can heat cause this problem? I ask because the plant was exposed to about 100 degrees of temps for a few hours. I have moved the plants to an ac room and I,m keeping temps in the low 80s now.

100 is bad so the heat stress

Lights are kept about 3 inches from plant, for vegg I'm using 2 four foot flourecent 56k bulbs. Right now I'm not feeding since I'm jusing miracle grow moisture control with fertilizer.
Can heat cause this problem? I ask because the plant was exposed to about 100 degrees of temps for a few hours. I have moved the plants to an ac room and I,m keeping temps in the low 80s now.

it looks like a sign of nute burn on the leaves also i could be wrong