API GH & KH Test Kit

The API GH & KH Test Kit measures both general hardness (GH) and carbonate hardness (KH) in freshwater aquariums, providing around 150 tests per kit. GH reflects the concentration of calcium and magnesium ions, which is critical for the health of invertebrates, livebearers, and hard-water cichlids. KH measures the water's buffering capacity, indicating how stable the pH will remain over time — low KH means pH is prone to dangerous swings. Each test is a simple drop-counting titration method, making results easy to read and repeat. This kit is essential for setting up soft- or hard-water biotope aquariums and for Discus and Apistogramma breeders.