what was the deficiency?

i had written my plants off as dead. they were three feet+ tall, thick stocks with good growth in 5 gallon buckets. recently they had started wilting severely and i though it may be overwatering. by this time i have lost some lower fanleaves which also irks me. i let them dry out and nothing changed, watered them after that and again nothing changed. last night i said **** it and watered them with schultz 5-15-5 plant food which if I'm correct is a flowering plant food. Only one of my plants is even showing preflowers. this morning i checked on them and they have since perked right up like some sort of god given miracle.

which deficiency could this be?

sounds like nutrient deficiency