A.P.I 5 in 1 Aquarium Test StripsA. P. I 5 in 1 Aquarium Test Strips provide quick and reliable water testing for both freshwater and marine aquariums, helping you maintain a healthy environment for fish and aquatic life. Simply dip and read to check key water parameters in seconds. Key Features 5 in 1 water testing measures pH, Nitrite, Nitrate, Carbonate Hardness, and General Hardness Suitable for freshwater and marine aquariums versatile testing solution Simple dip and read method