How to Read a Pool Test Strip Color Chart

Pool test strips are an easy way to get instant and accurate pool water test results. Select a test strip product that is compatible with your water type—chlorine or bromine pool, salt pool or spa.

Simply dip one test strip into pool or spa water at elbow’s depth and remove immediately. Shake once to remove excess water. Hold strip level and visually compare the strip to the color chart included on the bottle. Select the corresponding test result colors within 15 seconds of wetting. 

For expert pool water analysis results and personalized product and dosage recommendations, download the free Clorox® Pool app. With the app, you can enter visual results manually or scan-to-test with Clorox® Pool&Spa™ Multi-Use Smart Strips™.

For best results, never wipe or dry test strip after dipping. Read results in natural daylight. Keep wet fingers out of the bottle and store test strips in a cool, dry place. Test strips are not reusable. 

How to Read Your Test Results

Each test strip brand may be slightly different. The following explains how to read pool test strip results for Clorox® Pool&Spa™ Multi-Use Smart Strips™ and 6-Way Test Strips. For all other strips, refer to the product label instructions.

Total Hardness: Total Hardness measures the amount of calcium and other minerals in your water. Having water either too hard or too soft, combined with other balance factors, can damage pool equipment and surfaces. Maintain Total Hardness between 175—275 ppm. 

Total Chlorine: Total Chlorine is the amount of chlorine in your water, including free available and combined chlorine. Maintain Total Chlorine between 1—4 ppm. 

Free Chlorine: Free Chlorine measures the amount of chlorine available to sanitize your pool water, which is necessary to kill bacteria and control algae. Maintain Free Chlorine between 1—4 ppm. 

pH: pH measures how acidic or basic your pool water is. The measurement is critical to the health of your pool water. Having an imbalanced pH can damage pool equipment, cause swimmer discomfort, and hinder the performance of your sanitizer. Maintain pH between 7.2 to 7.6. 

Total Alkalinity: Total Alkalinity and pH are closely related. A low total alkalinity may cause fluctuations in your water’s pH and exacerbate low pH. Having highly alkaline water can cause pH to drift upwards. Maintain Total Alkalinity between 80—150 ppm.  

Stabilizer: Stabilizer measures the amount of cyanuric acid in your pool water. Stabilized chlorine lasts longer under direct sunlight and reduces the sun’s impact to chlorine loss. Maintain Stabilizer of at least 30 ppm.