Feature: 1. It is used to check the quality of your fish tank water and make your fishes healthier. 2. The PH paper cannot penetrate directly into the solution, first take some solution and drop a few drops on the test paper. 3. After dripping the solution on the test paper, wait for about 5 seconds, and then put the test paper on the color contrast card to find the corresponding PH value. 4. Widely used, the test paper can be used to test the PH value of water, cosmetics, fish tank water, human sweat, saliva, etc. 5. There are 20 sheets in a box, which meets your needs. Don't worry about suddenly running out of test strips when you want to test. Specification: Item Type: PH Test Paper Material: Paper Product Color: As Pictures Shown Product Weight: Approx. 150g / 5.3oz. Package List: 20 x PH Test Paper Note: The interval of each value of the PH test paper is 1PH, which can only be used for extensive testing rather than precise testing.