you seem to have solved the prob yourself if it was a over nute prob then usualy it yellows right along the serated edge of the leave and not just the tip.i have seen it begin at the tip but if the tip has been like this longer than a few days its probibaly a k deficiency.hope this helps the postman.
postmandave Reviewed by postmandave on . Yellow Leaf Tips hey all you gurus out there let me pick your brains - I am about four weeks into flowering and on most fronts the plants are fine. Green and healthy, thick stems and good buds. But many of the tips of the leaves - the very very tips - are yellowing. From what Ive read, this could mean two very different things. On the one hand, it could be a K deficiency. On the other hand, it could be over-fertilizing, with excess evaporation drying out the tips. But I am inclined to Rating: 5