I would raise your lights and switch to a 20/4 or 18/6 cycle.

It looks like you might be over watering as well, what's your current schedule?
Faddenator Reviewed by Faddenator on . Newbie has both yellow and tube shaped leaves Well..........Our indoor grow is in it's 3rd week. We have four plants that we started in pete pucks. We transplanted into an organic soil mixture of 1/3 peat moss, 1/3 vermiculite and 1/3 "organic" topsoil @ approx.1 week old. Soon there after, as the plants progressed, we began to get yellow and dried brown spots on the lower leaves. I'm pretty sure that our lights were initially to close. I'm also pretty sure that we were over watering based on my prior research here. Rating: 5