I started to see this problem few days ago , plucked some leaves out but I keep getting new ones , mostly top leaves, my PH is 6.5 , all other aspects are good
After reading I suspect it might be calcium deficiency but I’m here to ask the experts
Are you checking the levels coming out of your planters? Improper ph and to high ec levels can cause lockout. I would reccomend 18/6 for your girl as well. Give her some rest time. Also much cheaper growing with the least hours you need. Main reason I wont grow autos. Cost more money for inferior weed. Running lights at veg hours the entire grow would cost me way to much in hydro. Cheers