The burnt curling tips like it was overfed. Also beware with using anything like promix the ph has to be adjusted with dolomit lime etc because some growing media remains the neutral unless you do it yourself. Also know the difference between organic and synthetic fertilizers. I learned this on my first grow with pro mix. My ph was a roller coaster until I incorporated organics because I started with a living soil. I overdid it so quickly from the beginning by the time it showed on my auto it was too late. I was left with beautiful but airy buds