BioGuard Soft Swim Test Strips are designed to test pool water for the chemicals used in the Soft Swim program. These strips are easy to use and reveal results quickly and accurately. Pool experts recommend that Soft Swim Test Strips should be used weekly to ensure properly balanced water. This product works only with pools on the Soft Swim program. Each Soft Swim product is formulated to work specifically with the biguanide chemistry of the Soft Swim program.