My plant is 6 weeks into budding and it started to get rust colored spots on the top leaves and on the bottom leaves and they are starting to just fall off. now i have had my plants turn yellow when budding and i know that's not a bad thing but this is new and i know its not mites because i checked very carefully for them and there webs. i use 300 watts of CFL and i water every other day with light nutrients as recomended for the humboldt nuts i am using.
here are some pics, if anyone has any info on what this might be it would be helpful.

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“Music is the strongest form of magic.”
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Do your nutes also contain the needed micronutrients? I currently have a plant in Veg and had similar look of some leaves I described as rust spots. I purchased some micronutrients from local shop, everything is much better now.