Cal/Mag def?? Possibly some Heat Stress?

So these plants are outdoors in pots with FFOF soil. Been feeding nutes regularly for 7 weeks now with Humboldt Nutes Grow. The plants have been taking to this well . These probs started to appear about 10 days ago when the temps outside started to hit 100+. (not heat index either) Plant 2 where I put yellow arrows is where the heat stress began as the top leaves started to curl up and spiral, then became slightly crisp and now have browned as you can see in the pics. All the red arrows indicate what I believe to be a Cal/Mag def. These plants are getting direct sunlight from 1pm till around 7pm. Im watering around every 3 days now. Thanks for any info on pinpointing this problem. Anyone think this might even be a nute lockout? Thanks!!!

no one? Im starting to lean more towards heat stress at this time.

ph is out. what caused it could be many things. heat. bad wet/dry cycle. wrong ph to begin with,. i see stressed leaves with missing fingers on some. and tip burn means shes hungry

need to know ec/ppm in and ph in