hmmm.. i dunno I had some clones showing this before i even fed them. And now im seeing it on my girls that are 7 or so weeks into veg and im giving them about 1/2 teaspoon per gallon. The tips i guess could be because of that., but the coloring on the leaf i don't think can be overfeeding. I used the jacks classic last go around and they seemed to love it. If anything i think i fed them more last time.