These pool water test strips will provide you with extremely easy, accurate and instant readings of your pool water's chlorine, pH, alkalinity, and cyanuric acid (stabilizer) levels. These test strips will help you keep your spa / pool water safe and clean for your family's enjoyment. Dip a pool water test strip in your pool or spa water for one second and remove it immediately. Results in seconds! Test your pool water at each end of the pool twice a week. For spas, test before each use. 50 strips per bottle.