Those tubes run hotter at the ends. Try to keep the ends clear of plant matter. You can't really back those off. Anything further than 4 inches and your lumens are cut in half. How many lights are you running? The leaf tips are burnt so your running a hot solution. Bet you upped the nutes thinking she was hungry?
Have you tried to flush her and then start over with nutrients? You need to check PH. It can be and is most likely the problem.