Yea i dont think it was a runt it had the most vigorous growth from the start grew bigger and faster than the others. The problem seems to only really be with the main cola the side branches of the plant have decent bud development just want the cola to fatten since that is usually the best nugs you get off a plant. Heat is not the problem im running a 6 inch fan 400 cfm with a cooltube and fan controller temps range from 70ish light off to no higher than 84 with light on