Hygrozyme is a true breakthrough in enzyme based products that breaks down old root mass to allow for and stimulate new growth. Manufactured in an entirely unique way, Hygrozyme offers growers a number of advantages over competing products. It is bacteria free meaning that it has a virtually unlimited shelf life and there is absolutely no risk of introducing living bacteria into your system. The other benefit that this provides is that because there are no bacteria, Hygrozyme is the first and only enzyme based product that is suitable for use with Oxy-Plus. OMRI listed (organic) and highly recommended.