[PDX Dopesmoker]

Maybe its something else, but russet mites are pretty easy to get rid of so you might be better off with them. The horror stories are all exaggerated, my own first encounter was exaggerated because I boneheadedly spent like a month looking for a nutritional issue even though the problem had come in with a clone and had clearly spread from the clone to other plants, so it was obviously some kind of bug or fungus, but I figured it all out eventually, sprayed sulphur and only lost the initial clone.
Maybe you've got a sulphur deficiency? "sulphur deficiency" is going to become the polite way of discussing russets amongst squeamish types