Roots Organics HPK liquid bloom booster is a specially extracted natural source of phosphorus and potassium. Bat guano, which is renowned as an unparalleled source of available natural phosphorus, is combined with langbeinite which is a natural source of potassium, carefully mined from ancient sea beds in the desert of the American Southwest. Aurora Innovations has taken generations of gardening experience and distilled it into a distinctive, easy-to-use formula for the home and professional gardener. Carefully collected from specific global sources, Roots Organics HPK is minimally processed to preserve all of the benefits and amazing synergistic qualities found in Roots Organics exceptional ingredients.