API Alkalinity (KH) Test Kit API Alkalinity (KH) Test Kit measures carbonate hardness in freshwater and saltwater aquariums, helping monitor buffering capacity, pH stability, and alkalinity conditions that affect fish, plants, and corals. API Alkalinity (KH) Test Kit for Carbonate Hardness and pH Stability Carbonate hardness helps buffer aquarium water against rapid pH swings. The API Alkalinity (KH) Test Kit gives aquarists a straightforward way to monitor KH so they can identify low buffering capacity or track changes after water changes, additives, or source-water adjustments. Freshwater and Saltwater KH Testing for Buffer Control Measures carbonate hardness, also known as KH or alkalinity. Suitable for freshwater and saltwater aquariums. Helps prevent pH instability caused by low buffering capacity. Useful for determining when pH buffers may be needed. Important for marine aquariums where proper KH supports healthy coral growth. Fast liquid test format using a single KH test solution. Good for routine water-quality monitoring and troubleshooting pH swings. API Alkalinity (KH) Test Kit Aquarium Use Notes Product type: liquid carbonate hardness test kit Tests: KH / carbonate hardness / alkalinity Use for: freshwater and saltwater aquariums Sample size: 5 ml of aquarium water Recommended frequency: weekly testing for regular monitoring Useful for: pH stability, buffer dosing decisions, and reef alkalinity awareness API Alkalinity (KH) Test Kit Directions Rinse the test tube before testing. Fill the test tube with 5 ml of aquarium water. Hold the KH test bottle vertically for uniform drops. Add test solution according to the instruction booklet until the required colour change is reached. Count drops as directed to determine carbonate hardness. Record results and compare them against the desired KH range for the aquarium type. Rinse the test tube after use and do not pour test contents back into the aquarium. What's Included One KH test solution bottle One capped test tube One instructional booklet
