Pond Care® AMMO-LOCK® has been uniquely developed to eliminate the toxic effects of chlorine, chloramine and ammonia that may be present in municipal water used to fill ponds. Fish waste, decomposing algae, plants and uneaten fish food produce ammonia. Ammonia, which is a colorless and odorless toxic chemical, is the number one killer of pond fish. AMMO-LOCK also detoxifies harmful levels of ammonia that can occur in pond water from overfeeding and overstocking of fish. AMMO-LOCK's patented formula instantly neutralizes both chlorine and chloramine and effectively "locks up' any potential ammonia or immediate ammonia up to 5 ppm per dose. Although ammonia will still be present in pond water, AMMO-LOCK converts the ammonia to a form that is nontoxic to aquatic life; this nontoxic form actually serves as a source of nutrition for nitrifying bacteria in the biological filter. Ammonia build-up can occur whenever starting a new pond, before biological filtration becomes active, or when there is inadequate biological filtration. You should also use Pond Care® Stress Zyme® to speed the development of the biological filter.