I'm using Fox Farm, the dry all purpose, and tomato and veg "Happy Frog" after years of Epsoma. Not sure why I made the change, other than lots of warnings about organic fertilizers in containers (I garden in Earthboxes). But Fox Farm is organic too. In fact EVERYTHING seems to be labled organic.i've used Cal Mag in hydroponics, but don't have a control, so who knows?
https://www.amazon.com/FoxFarm-FX140...rog+fertilizer
About $10 at my local Ace.
Cal Mag
https://www.amazon.com/General-Hydro...ywords=cal+mag