Grow Mediums Recipe for soil additive?

[SHRED]

I have been using Mephisto Super Soil powder with great success.
I'm interested in making my own similar additive.
Does anyone have a recipe for making a similar powdered additive that's mixed in the lower half of container soil?

 

[Alasgun]

Agricola soil minerals is a good option if you want a quasey super soil. I still let it set a couple weeks after mixing before use.