My first grow. 3 plants in 36x20x60 closet tent, Blackstar LED, Subcool Super Soil

Delahaze is sickly looking. She has brown/orange spots pretty much all over and her stems are dark purple as well. The other 2 girls are doing fine. I’m not sure how I will proceed with Dela. I will just monitor for now. Early research points to a calcium or magnesium deficiency, not sure which if it’s even either of those. I would have rather this happened to either of the other 2 plants because Dela was my early favorite. She also happened to be a freebie thrown in from Attitude (not that there’s any correlation.)