This water test strip can detect pH, total alkalinity, hardness, copper, iron and other 16 parameters. Take 5-10ml of sample and take the supernatant to test after standing. Immerse the reaction area of the strip in the solution to be tested for 1-2 seconds, take the strip, and drain the excess water, after 1 minute, compare the color of the reaction area of the strip with the color chart to determine test value of the solution. The comparison time should be controlled at about 60s, too long or too short will affect the reading. This water test kit allows you to quickly and accurately test your drinking water. And the results are fast for about 1 minute, it's very easy to read by following the color charts and instruction manual. This test paper is made of PET, which can precisely detect the water quality. The box is 13cm high, 5.4cm long and 5.2cm wide. You can use this product to test water source including drinking water, aquarium, swimming pool, spa, industrial water, pond, hot spring water. Item Name: Water Test Strip Material:PET Test Time: 60s Storage Condition: 2 Degree Celsius - 30 Degree Celsius at Dry Place And Avoid Light (Store at 2 Degree Celsius - 8 Degree Celsius) Term of Validity: 24 Months (2 Degree Celsius - 30 Degree Celsius at Dry Place And Avoid Light) Size:13cmx5.1cmx5.2cm/5.12inx2.01inx2.05in Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. When removing the strip, do not touch the reaction end of the strip, so as not to contaminate the strip and affect test results. After taking out the required number of test papers, keep the remaining test papers sealed and protected from light. Try to keep the liquid to be tested as colorless or light-colored. Before testing the liquid with too dark color, it can be dehydrated with activated carbon adsorption. If the liquid to be tested is relatively turbid, let it stand for a while, and take the clear part for testing after it settles. Package Includes: 50 X Water Test Strip