Noticing some small spots on some fan leaves a few weeks into flowering. Also some discoloration ..appears to be purple-ish. Not sure if there are multiple things going on. Maybe some Cal deficiency?
I agree, looks like too much nitrogen (dark green,shiny leaves and claw)
spots look suspiciously like spider mites. I would check that first. If not then lower N before you add calmag.It has N in it also.
I think you have salt buildup. If you have a ppm meter, measure your runoff ppms. It's better if you measured it for awhile and could see a trend. When my ppms reach 2500 I have trouble. It might be good to feed half-strength nutes next time, enough volume for 50-100% runoff.
When you feed/water, do you get runoff? How much? 20-30% each time will reduce build up.