what iam looking at , those burn spots are coming from you watering with nutes. when watering try not to get any of the water on the leaves, this has happened to me all the time with my lower leaves. before i installed an a/c unit in my box , i would sweat up there with all that heat and sweat on the leaves and that made some of my leaves have yellow spots on them as well. so the yellow spots are from watering with nutes. now if the entire leaf if yellow thats has to do with over nute.