Mykos is very-specific specie of Mycorrhiza that works faster and stronger. If you haven't heard of mycorrhiza, it's a microbe that builds root mass and increases plant uptake of nutrients and water. With more roots, you get more fruits. Mykos grows the biggest and best fruits, vegetables, flowers, and herb! It also helps 'leap start' new transplants and shield roots from shock and disease. Mykos is a beneficial additive; it may be used with any nutrient line. Great for vegetables, fruits, & herb. Some sizes may not be stocked in all locations.