Gorilla Glue Autos x3 - Fast Buds - Coco

Blue and Red started showing a couple rust spots like the 3rd plant initially had. Epsom not working. Trying to reduce extra stuff (b52 / sensizym) and remove epsom. Supplement with 1ml cal mag per gallon. Improve air flow with defoliation / lollipopping. Blue - 23" - Happy Red - 30" - Happiest plant 3rd plant - 23". This plant is having problems. Not sure if it's cal/mag, lockout, or septoria. Have moved this plant downstairs to it's own tent. Didn't train, lollipop, or scrog this plant which could have caused fungus. Or it's because it's in late flower, not sure.