The API® AMMONIA TEST KIT measures ammonia to help prevent fish loss, as ammonia is the number one stressor and killer of tropical fish. Ammonia is released into an aquarium in the forms of uneaten food, decaying organic matter, and when fish release it through their gills, urine, and solid waste. The API AMMONIA TEST KIT is a mercury-free, salicylate test for fresh and saltwater fish, and measures ammonia levels from 0 to 8 ppm. Suitable for Freshwater & Saltwater aquariums Helps to accurately keep track of ammonia levels Easy to use kit with quick results Use during regular fish care, addressing water problems, or setting up a new aquarium