They look hungry for nitrogen to me.. I would try bumping your PH to 6.5 for a few days and see if that changes, if not then consider supplementing with some CalMag+ (+ being Iron or Fe).
Too much light is very unlikely I'm running Growers Choice ROI-e720 6" from the canopy and no burn or light issues other than the plants loving it.
Seems like you went full throttle with your room setup why would you choose to use Jacks? Personally all the Jacks weed i've smoked has tasted bland and cheap. You get what you pay for.
Here are 4 plants (week 4 bloom) growing in the "AutoPot XL 4 pot System". Nutrients are Botanicare CNS17 base with Hydroplex @ 5.8-6.2 PH (I like to dance it around) and the plants are loving it. First time running the CNS17 1 part nutrients but obviously they're pushing some nice plants. Strain is creamsicle.
Light: Growers Choice ROI-e720 LED
Medium: Royal Gold Tuper (Next time I'm running Mother Earth coco/perlite with the bottom 6" of the pot being #3 chunky perlite for quicker feedings)
Nutrients: CNS17 Grow, Bloom & Ripe
Supplements: Botanicare CalMag+, House & Garden Drip Clean & occasionally 1 oz of 35% h2o2 into the 12 gallon reservoir probably once a week to ensure things stay sterile and clean.