On their homepage GHE writes about the Bio Roots activator:
    "*  It stimulates the development of micro organisms in the root mass and promotes the growth of roots and rootlets.
    * It improves the root’s biotope and hardens the root cap. This activates the development of a vigorous root mass and a better settlement of the plant in its environment.
    * It allows better resistance to disease and pathogenic moulds (powdery mildew, dumping off in seedlings and cuttings, etc)."

Bio Roots is made of natural amino-acids extracted from plants and fruits, and contains essential oils. It stems from ecological recyceling with no addition of chemicalm and synthetic products.
 

According to the producer, you need 2ml Bio Roots for 10 liters of water, that means you need ca. 2 drops per liter.