Test for: Free Chlorine, pH, Total Alkalinity, Cyanuric Acid, and Salt (as sodium chloride) The AquaChek Salt System Test Kit contains the essential tests for maintaining clean, healthy water and the efficiency of salt generator systems. These include: Free Chlorine, pH, Total Alkalinity, Cyanuric Acid, and Salt (as sodium chloride). It’s Fast, Easy, Accurate testing in a convenient duo-pack! To keep you pool water clean and healthy, test the water at two ends or sides of the pool a minimum of twice a week! If used in a spa we recommend testing it before and after each use. It’s also a good idea to write down your results each time you test.