I had some AK 48 which pulled that rusty leaf routine while it was vegging. Like to scared me to death. Can't imagine it being some nute deficiency because I was using some high dollar organic stuff which I have used extensively and never had the problem in question. Was two lower fan leaves so I cut them off and throwed them in the cull pile and none of the others repeated the phenonom. Wanted to lollipop it a bit anyway. I couldn't quite figure out maybe it was kind of disease or results of the genetics. Never growed that brand before and knew it put off funky colors since it has some White Widow in the blood lines. Kindly let us know when you get a handle on whats up there.