API 5-IN-1 TEST STRIPS Freshwater and Saltwater Aquarium Test Strips 100-Count BoxContains one (1) API 5 IN 1 TEST STRIPS Freshwater and Saltwater Aquarium Test Strips 100 Count Box Monitors levels of pH, nitrite, nitrate carbonate and general water hardness in freshwater and saltwater aquariums Dip test strips into aquarium water and check colors for fast and accurate results Helps prevent invisible water problems that can be harmful to fish and cause fish loss Use for weekly monitoring and when water or fish problems appear