thats just light burn, tips will do that if your light is too close.MizzMellow, here is a picture of the leaf with the brown tip. These are young plants and have not been given any nutrients. I have not checked the pH of the soil. Last night was their first night under two 65W 6500K CFL's. Prior to that I used one 300W 2700K. I was reading the thread on super cropping and wonder if that is an option in one gallon containers or should I wait until after transplant? Thanks for your help.