I mean I agree with everyone else too, your plants will fatten up in the next few weeks. But the light could be a little ways away . My light is aircooled from the top and doesnt have tempered glass, so its really not getting the benefit of being Cooled. So I keep my light about 8 inches above the top. I just put my hand right above the tops of the plants to see how hot it gets. Are you using Co2, and ferts?