I was wondering the same thing about the langbeinite . . . I don’t use it. I DO make a compost tea with molasses in it. Regular Blackstrap molasses that you find in the store is unsulphured (it will say so right on the front of the bottle).
The molasses increases microbe activity bc it feeds them sugars, which also goes into the soil. VERY good stuff. I’m also new to this BTW but growing organically is THE WAY to go. My buddies who use bottled nutes tell me what I’m doing is too complex for them but that’s what I think about their nutes. If you make a good soil, mother nature will take over.
You can also re-use the soil after harvest and it is a much richer blend so the next harvest will be even better.
What do you put in your compost?