Can anyone diagnose my problem about 4 or 5 post's back.
I am in
NO way qualified to answer your question since I don't have even one grow under my belt, but I did take a look through my little book which has a small section on MJ ailments. I'm
GUESSING it might be one of the following:
Calcium deficiency: The large leaves at the top of the plant are effected, but not the bottom-most leaves. Yellow spots surrounded by a very brown rim appear, the spots look like rust spots. The growth slackens and production decreases.
Magnesium deficiency: Pale chlorosis spots on leaves of an average age, these discolour to yellow and rust-coloured. If the deficiency is severe, spots will also appear on young leaves. (Judging by your pics and the pics in the book, it looks more like this might be the problem.)
(Also, an overdose of potassium prevents the admission of calcium and magnesium, symptoms of potassium over dosage: burning and dehydration of the leaves.)
Or you could always ask the experts over here
https://www.rollitup.org/marijuana-plant-problems/157345-have-plant-problem-check-here.html
Em