do these plants have a nutrient problem or something?

Hey, 1st post here... Started growing these kush clones on my deck in late april, theyve bin pretty healthy up until about a month ago. Im not sure if ive bin using the right fertilizer, a grower told be to get B1... did i get the right B1? (see pic) I noticed the lower leaves turning yellowish and other leaves forming brown spots ( see leaf pic). They were getting big so i started LST'ing them 5 days ago, the other night it was raining so i put them under some shelter, overnight it was 13 degrees C and when i looked at them the next day the 2 smaller ones have purple on the stems and several brownish leaves (like in the leaf pic)

Thats all the info i have so help plz

looks like nitro and magnesium deff this chart helps
http://www.weedfarmer.com/cannabis/tables_guide.php