Feature: 1. Water quality test paper is packaged in a dry airtight bottle and airtight bag, which is durable. 2. PH test strip is simple to operate, no other supplementary materials are needed. 3. Classical colorimetric analysis, multi‑level detection requirements, visual readings with colorimetric cards. 4. The test paper only takes 0‑1 minutes, which is easy to carry for outdoor testing. 5. Suitable for aquarium, swimming pool, spa, industrial water, drinking water, pond, hot spring water, etc. Specification: Item Type: Water Quality Test Paper Material: Paper Weight: Approx. 35g / 1.2oz Specification Model: 50 Strip/Bottle Test Items: PH, total alkali, nitrite, residual chlorine, total chlorine, hardness, bromine Storage Condition and Validity Period: 1. Storage condition: Store in a dry place at 2℃~30℃ and protected from light (2℃~8℃ is better). 2. Product expiration date: Store in a dry place away from light at 2℃~30℃, and the validity period is 24 months. 3. Validity period when opening the bottle: After opening, the cylinder cap needs to be sealed and stored in a dry place at 2℃~30℃ and protected from light. The validity period is 6 months.. Package List: 1 Bottle x Test Paper (50 Strip) Note: 1. When removing the test paper, do not touch the reactive end of the test paper, so as not to contaminate the test paper and affect the test results.2. After taking out the required number of test papers, keep the remaining test papers sealed and protected from light.3. 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 period of time, and take the clear part for testing after it settles.