Whats this help?!

So this just randomly happened, just did a fresh nute change wednesday and havent noticed anymore on the new growth. I have a 600 watt led that I believe was too close to my biggest plant so I backed it up a few inches too. Nothing on the bottom of the plant and so far nothing on the new growth just that set of leaves and only on that plant. Was it just light burn? Plants look healthy otherwise I think. Use masterblend, urb, kelp, and calmag. I'm about to switch to flower and want to make sure it's taken care of for sure. First grow also bag seeds

Calcium def....a little cal-mag will clear it up. Just remember...damaged leaves wont recover.

Okay so this was the first I put calmag in my nutes so hopefully it stays gone now! Thank you so much!