What kind of light bulbs are you using and how old is your plant? Because mine also did that when even my cfls were not even touching and temp was good. If it is a youngen ( 0-4 weeks old) it will need about 2 inches of space from a cfl. If its anyother light source also try to give it more clearence and see how it goes.please help im using the water farm hydro system and the ends of some of my leaves are turning yellow/curling.. im using the right amt. of the flora series nutes and the temp. is good. im not over or under watering i have my pump running 15 min. out of every hour. please help