Fish continually release ammonia into the aquarium through their gills, urine and solid waste. Uneaten food and decaying organic matter also add ammonia to the water. Even small amounts of ammonia stress fish; large amounts of ammonia will kill fish. Ammonia is the #1 killer of freshwater fish. API AMMO-LOCK Freshwater and Saltwater Aquarium Ammonia Detoxifier works instantly to detoxify ammonia, chlorine, and chloramines in fresh and saltwater aquariums. It protects fish cells and promotes healthy gill function by eliminating fish stress caused by ammonia. API AMMO-LOCK Ammonia Detoxifier Freshwater and Saltwater Aquarium Treatment does not remove ammonia from water; it converts it to a non-toxic form. Aquarium water will still test positive for ammonia until it is removed by the biological filter. For best results, use as directed on the product label. If your aquarium tests positive for ammonia, do a partial water change, then neutralize the ammonia with API AMMO-LOCK Ammonia Detoxifier Aquarium Treatment. With API Aquarium products, it?s easy to keep a beautiful saltwater, freshwater or reef aquarium. For over 50 years, API has been creating innovative, research-driven solutions that make it easier to care for your fish and aquarium. API Aquarium Treatment Supplies are designed to work in conjunction with each other to provide best results to control algae, promote healthy bacterial growth and help control and cure fish diseases and conditions such as ich and fin rot. They work to provide a safe, hospitable environment for fish such as tropical community fish, cichlids, goldfish and more. With API, you can spend more time admiring your fish, and less time scrubbing your tank. Make sure to use all products as directed in order to ensure the best results.