The plants now finish the 10th week start the 11th...

yellowing at top isn't N, and seem lush underneath? Try moving lights 4-6" further away and see what happens.. if light-related, probably won't heal much... it doesn't look like light burn, though either. I think you are more than 2 weeks from harvest, so you will need to feed soemthing between now and then, but maybe an extra irrigation of water only. The red leaves are a sign of overfeeding too, think P? that's a toughy, i'd take the safe route.. see if lights help a bit higher and whatever your normal fert-water cycle is.. add an extra water between.