Looks fine to me.
I noticed that if I overwatered when I was under t5 it would cause that.
Frankly, I would pinch all the lower growth off that is below the level of the pot. T5 doesn't penetrate very much foliage. How close is your light to the plant? I would keep mine about 12 inches from the top of the growth, depending on if I was using my 4 bulb or my 8 bulb.
