4 in 1 Aquachek Pool Chore Tester, it will test the fundamental measures for maintaining your pool water, free chlorine, pH, alkalinity and cyanuric acid. Testing yourself will prevent you from becoming over - stabilized, which will lead to water degradation. Advantages: Strips provide reliable, instant, accurate results It will allow you to keep your water balanced He can also test your spa A very good reliability rate It measures: free chlorine, pH, total alkalinity and cyanuric acid (or stabilizer rate) in water Features: Water analysis using strips Number of strips: 50 Result time: 3 to 5 minutes Recommended frequency for pool testing: 2 times/week Aboveground, in - ground pools, spas Reference: AQC - 470 - 0005 Tip: In order to obtain a complete diagnosis, test the pool water at both ends and compare the results. For a spa, it is recommended to test the water with Aquachek before each use. Packaging: 1 x 4 in 1 Pool Aquachek Chore Tester Delivered in its original packaging