Classic reliable mixture of ”CVG” which is Coco coir, vermiculite and gypsum. Hydrated to field capacity and sterilized.
We also offer a CVG based mix that has shredded straw, which provides additional nutrients and alters the structure of the substrate in a way we find favorable.
Both perform roughly the same but straw maybe better in certain circumstances.
One 5 lbs bag of bulk substrate and one 3 lbs of sterilized grain is a great ratio to use. It seems to balance nutrient density and moisture content well for fast colonization and good yields.