As you probably know, keeping your aquarium's ammonia levels low is a vital part of ensuring the long-term health and vitality of your species. In fact, despite the fact that it's constantly released into your fish's habitat through waste and material breakdown, ammonia is the number one killer of tropical fish. The API Ammonia Test Kit for Freshwater and Saltwater Aquariums can help you quickly, easily and accurately keep track of your aquarium's ammonia levels. It measures ammonia levels from 0 to 8 ppm and has a development time of just five minutes. With the right ammonia reader, you'll be able to closely monitor fish tank toxins and adjust your filters and media to eradicate harmful ammonia. Use this test kit during regular fish care or when addressing water problem-solving issues. Every API Ammonia Test Kit strip is mercury-free, so it's safe for freshwater fish.