Well I'm in soil and don't use superthrive in bloom, but I do use calmag atm simply because my plants are recovering from a coco experiment gone horribly wrong, lol!

In the future, I don't expect I will need the calmag, as my old soil method included some bone meal and a bit if fish glop mixed in to the soil of the last transplant, and myco-stim to help release it, and I occasionally add either flora micro or algoflash to the feedings... like, once every week or 2.