The soil in this video is made up of
Recycled Soil
Additional Perlite
Compost
Worm Castings
Neem Seed Meal (Neem Cake) 1/2 cup per cubic foot
Fish Bone Meal 1/2 cup per cubic foot
Shrimp Shell Meal 1/4 cup per cubic foot
Kelp Meal 1/2 cup per cubic foot
Langbeinite 1/8 cup per cubic foot
Lime 1/8 cup per cubic foot
The recycled soil, having cannabis previously grown in it, is already primed for more (plant and soil communicate to provide what is best for the plant, this relationship begins in fresh soil but it’s already familiar and ready to go in recycled soil). The compost and worm castings provide plenty of the readily available nitrogen the plants require in early growth. The neem seed meal and shrimp meal provide slow and steady nitrogen throughout the plants life cycle along with a host of your necessary micronutrients (calcium, magnesium, chief among them). Since you’re not overloading the soil with high nitrogen inputs that heat up the soil (this cooking process is nitrogen leaving your soil by the way!!!) so you have to wait to plant in it, you’re providing already readily available nutrients, and you’ve got a host of amendments that will become available over the plants life cycle as you need them because of the microherd you’re supplying with the compost and castings. These plants will need nothing but dechlorinated water their whole life cycle.
If you don’t have soil to recycle or you’ve ruined your medium with salty fertilizers (you can compost it to remove the harmful salts), an even parts mix of perlite/peat moss/compost is a good base point. You can substitute coco for peat, just use less lime for coco