Promote A Healthy Ecosystem Eliminate Excess Nutrients Seed & Maintain Biological Filters Use Pond Logic® Nature"s Defense® to promote a healthy and thriving ecosystem in your pond resulting in clear water. Nature"s Defense® comes in no-mess, easy-to-apply water soluble packets. The natural bacteria in this product instantly activates as it hits the water and multiples every 20-40 minutes to start digesting the dead organics in the pond, such as fish waste, uneaten food, and leaves. Nature"s Defense® eliminates excess nutrients such as phosphates and nitrogen. Use Nature"s Defense® to both seed and maintain your biological filters, resulting in reduced levels of ammonia and a crystal clear pond.Pond Logic® Nature"s Defense® can also be found in the DefensePAC®.