Noot burn and looks quite done to me! When you have 85% brown hairs or more it is probably done and not going to get much better and certainly no bigger at this point. Whack 'em, smoke 'em, plant some mo'. Plus, you should back off on nutes altogether a week or so out and just flush with fresh water. This looks like the plant is mature and you kept giving it nutes when it was unable to take more due to maturation. If they are 8 wks, they are done!