leaf mark identification

Watch your lights, nitrogen and see if maybe its over watered. 1 thing at a time so you can see the result of whatever you use to fix it. Hope that helps dont forget worst case scenario only use bottle disttle water till things cool out for a few days

Alba gu braith. If it starts at top of plant where all the new growth starts, then it is immobile nutrients. So it rules out npk. Leaving secondary/trace nutrients. I wouldn't say it fits nutrient excess/deficiency. Looks more like light burn. Make sure top of canopy is not going over 86. Edges of leaves are upticked which could be due to chlorinated water. Do you let your water sit 24 hours prior to watering? Good luck

This is heat stress, possibly from being too close to your lights... You say in your diary the lights are 18" above the plant but perhaps this is not accurate? I would try pulling those tops over GENTLY to get them away from the lights a little bit more. Doing that will also allow more light down below but that's just an added benefit and NOT a comment that I think you NEED to get more light down below... Good luck!

I assume you are top dressing with gaia green. Are you following their recommendation of 1 tbsp per gallon? Also, I would not add so frequently, minimum 3 weeks in between top dressing. You may be giving your plants too much nutrients.