I found the problem: your day has 26 hours (18+8h) 😂
But on a serious note, I'd agreed with the other people here. It looks like a nutrition burn. Maybe your pH / ec meter isn't exact / broken or the fertilizer concentration is too strong. I'd try to flush everything and just use plain or even destilled water (but I don't know to much about hydroponic growing)
Anyways, good luck with your grow, you got this 👍