Contains one (1) API NITRITE TEST KIT 180-Test Freshwater and Saltwater Aquarium Test Kit, including 1 bottle of testing solution, 1 colour card and 1 glass test tube with cap Helps monitor nitrite and prevent invisible water problems that can be harmful to fish Accurately detects high nitrate levels from 0-5 mg/L Prevents high levels of nitrite which inhibit fish respiration and suppress their immune systems Use for weekly monitoring and when water or fish problems appear