100% brand new high quality Upgrade: The total hardness test strips have 5 LEVELS and 4 PARAMETERS that improve the test efficiency and accuracy makes these strips more trustable, you don't need to visit a hardware store or wait for someone else to check the quality of your water, save your money. Easy to Distinguish: The water hardness test strips turns from green to purple for the water hardness 0-425ppm=(0-425mg/L), the color difference is more obvious, easier to compare the strip color to the color chart. In additional, the test strips made of environmental protection material of PLA. Quick Read Accurate Result: Submerge test strip under water for 2s, Hold it still in the air for about 15s, then match up the colors of the strip to the back of the bottle to get your readings, only take 17s. Apply: The water hardness need periodical testing and monitoring. You can test all water sources including home faucets & taps, well water, fresh and salt water pools, spas, hot tubs, drinking water, aquariums and many more. Features: 1. High quality Water Hardness Test Strips are very sensitive to the environment and changes to temperature. 2. If you have a water softener installed, check its effectiveness quickly by taking a water sample and testing with the strips. 3. The strip can help your fish grow well. Some fishes need it soft, some need it hard, and some very hard. Maintain the amount of hardness in the water by testing regularly. 4. Hard water leaves mineral build up in pipes and hastens corrosion. Ensure that soft water runs in your system by testing often. 5. Avoid hard water stains in your kitchenware by testing the water daily. Hard water also reduces the lather of soaps, making it less efficient. Specification: Size: 4x4x11cm/1.57x1.57x4.33inch Package Weight: 54 g Quantity: 50 Strips/100 Strips Note: 1.Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you place order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you Please allow 1-2cm errors due to manual measurement. Package includes: 1 Set Water Qualtiy Test Strips