What medium? Is that an aero setup? Soil? Hydro? How often do you change the resevoir? They look like they are starving. Either for nutrients or lumens. Since you are feeding them, I'm leaning towards lumens.
A 250 watt light should be 12-18" away from the tops of the plants. If I were you, I would move the light quite a bit closer and check them a couple of days after. If you are seeing no change, then try nutrients. If it is soil or hydro, flush your medium and up your nutes 5% per day until you see a -*slight*- burning on the leaf tips. Once you see a burn, back them off 5% or so. You are using the "Hesi Hydro Growth" nutrient?
Also, on that fourth picture you posted there is a strange abrasion on the uppermost leaf. It's hard to tell because it is so small, but if that patch lengthens you could have leaf miners. Attached is a picture of a leaf miner infestation.