Keep your fish healthy and thriving by testing your aquarium water's KH levels regularly with this easy-to-use API CARBONATE TEST KIT for freshwater aquariums. API CARBONATE HARDNESS TEST KIT helps prevent pH problems by stabilizing aquarium pH in fresh and saltwater aquariums. Fast, easy, and accurate testing evaluates KH levels in aquarium water, so that they may be corrected if too low or high. Water with low KH is susceptible to rapid pH shifts, stressing fish and increasing the risk of disease. In marine aquariums, proper KH levels are necessary for healthy coral growth. Kit contains 1 KH test solution bottle, one instructional booklet, and one capped test tube. With API aquarium products, its easy to keep a beautiful saltwater, freshwater or reef aquarium. For almost 60 years API has developed premium solutions with proven and effective results for your family and ours. API offers a range of testing kits, water conditioners, and nutritionally superior food, because were dedicated to making a better underwater world. They work to provide a safe, hospitable environment for fish such as tropical community fish, cichlids, goldfish and more. At API, we understand the rewards and relaxation of fishkeeping because we have a passion for fish too.