Another small, or big, issue

[Gabby987]

Hello again.
Random leaves turning crispy.
Grandaddy Purple
Soil
Heat 77 to 80
Humidity a little high at 55 to 60.
3rd week flower.
I notice this plant had some signs of light stress and I moved away from lights.
I have been battling spider mites on a couple of plants,, and I am currently using SNS 217C every 3 to 5 days on all plants in flower room at lights out.
I have not found mites or eggs on this plant.
Suggestions?

 

[Justin Goody]

I would say it’s either pH fluctuations in your water, or you may just need CalMag for a few feedings.
Heat/light burn would start at the edges and curl first.

 

[Gabby987]

Thank you. I doubt it's Ph because I ph all my liquids 6.3 to 6.6.
I didn't thing of CalMag. I will feed now, it's due for watering