How soon after the feeding did the leaves start to brown-up? And no...it's not normal for this to happen.

Seedlings in soil shouldn't get any addition of nutrients till between the 3rd and fifth set of true leaves. (approx) Also, how long ago did you add the nutrients?

Are you in coco or soil...? If in a potting soil, next time, you might want to use the proper troubleshooting form. The one you filled-out is for hydro. The soil form is just above it in the same troubleshooting form thread.
Rusty Trichome Reviewed by Rusty Trichome on . helppp, browning leaves my one biggest plant is merkin, on its 3rd node and on the first node, the tips of the leaves are starting to go brown and point up =/ i would post pics but i havent posted 50 times yet What is your experience level? (first timer, novice, experienced...) first timer What type of hydro set-up are you running? not Your Equipment: A) Type and wattage of lights. (MH, HPS, CFL's, tube fluorescents, LED's)=http://www.htgsupply.com/viewproduct.asp?productID=51907 for 3 plants B) Distance Rating: 5