33% of mix that has perlite? Or am I supposed to exclude the promise perlite?
33% of your total soil mix. pearlite, or crushed lava rock, pumice, growstone (recycled exploded glass which is basically pumice), rice hulls, w/e you like!
a good base recipe i use with no NPK amendments is:
33% aeration/drainage made up of whatever is listed above, can be any combination you like
33% compost, be it earth worm casting, compost from garden/veggie scraps, ancient forest, or a mix of any
33% peat (can use leaf mold or coco if you desire)
so basically the base mix is 1:1:1 ratio. you can make slight tweaks in any direction to suit your needs.
to a cubic foot (7.5gal) of that soil base I add: 3 cups of rock dust blend of whatever is easy to resource for you (glacial, basalt, azomite, greensand, or any other), 1/2cup of oyster shell flour to help with ph (lime could be used 1/2 and 1/2 with oyster shell flour)
you can also use biochar no problem in this mix at no more than 10% of the total soil mix.