The medium’s purpose is to anchor the roots and trap the nutrients and water so that the marijuana plant can make use of them. Any medium that can do this and also hold adequate amounts of air will suffice. Many mediums—like lava, ceramic beads, perlite, and other commercial materials—work just fine. Although the nutrients could affect the marijuana plant’s health and growth, they don’t really affect potency at all. Light intensity is also responsible for plant and bud growth and the potency to some extent. Still, the main factor that affects potency is genetics. The genes determine both potential yield and potency more than anything else.