Testing water parameters weekly helps prevent invisible water problems that can be harmful to fish. 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. Small amounts of ammonia stress fish; large amounts of ammonia kill fish. Ammonia is the #1 killer of freshwater fish. The API AMMONIA TEST KIT for freshwater and saltwater squariums contains two liquid dropper bottles, easy-to-read instructions with information on how to test and correct unsafe water conditions, two color charts and glass test tube with snap-tight cap. This test kit reads ammonia levels from 0 to 8 ppm. Use the API API AMMONIA TEST KIT several times a week for 4-6 weeks when you start a new aquarium, and then use it weekly for monitoring or when problems occur. This aquarium test kit is for use in freshwater and saltwater aquariums. 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.