1Just immerse a piece of test paper in the water for about 2 seconds, take it out and lay it flat, and then compare it with the color chart after 15 seconds. 2It is recommended to test in the water twice a week to get the best results so that you can know whether the water quality is in a healthy and clean state. 3When the water quality deteriorates, a large change in the pH value is a warning, recommended to check the pH value every morning and evening, at the same time. 4Suitable for drinking water, aquariums, swimming pools and spas, sewage and other liquids, and can also be used to test hot tubs 5Can quickly detect residual chlorine, PH value and total alkalinity in water of fish tank. Item Type: Aquarium Test Strips Material: Test Paper Color: As picture shown Weight: Approx. 30g/1.1oz Purpose: Rapid detection of residual chlorine, PH value and total alkalinity in water Shelf Life: 24 months