Features: 1With this test paper, you can control 7 values ??that are crucial for good water quality: pH (acidity), total alkalinity, hardness, bromine, NO2 (nitrite), NO3 (nitrate) and total chlorine. 2 These values ??determine how healthy your aquarium is. Abnormal values ??can cause problems. 3 Good water quality is essential for the fish and plants in your aquarium. 4 Regular testing of water quality values ??helps ensure that fish live healthy and happy lives. 5 Easy to use. The packaging includes 50 pcs of test strips, which can be used for a long time. Material: PET Test time: 60s Shelf life: 2 years Certification: FDA, CE, ISO Test items: PH, total alkali, nitrite, residual chlorine, total chlorine, hardness, bromine Scope of application: drinking water, aquarium, swimming pool, spa, industrial water, pond, hot spring Testing method: 1. Open the parafilm, remove a strip of test paper, and immediately close the cap. 2. Immerse the reaction area of ??the test strip in the solution to be tested for 1-2 seconds, remove the test strip, and dip the excess water with paper. 3. After 1 minute, compare the color of the reaction area of ??the test strip with the color chart to determine the test value of the solution to be tested. 4. The colorimetric time is optimally controlled at 60s, too long / short time will affect the reading. Precautions: 1. Do not touch the reaction end of the test paper when removing the test paper to avoid contaminating the test paper and affecting the test results. 2. After removing the required number of test strips, store the remaining test strips in a sealed and dark place. 3. The liquid to be tested should be kept as colorless or light-colored as possible. Before the liquid with too dark color is detected, it can be dehydrated by adsorption with activated carbon. If the liquid to be tested is turbid, let it stand for a while, and then take the clear part for detection after settling. Package Included: Water quality test paper * 50