These Jed Pool Tools Inc. 00-490 50-Count Pool and Spa Test Strips are ideal to check for free chlorine bromine alkalinity pH and total hardness. They help to maintain the health of a pool with ease. The pool water test strips are easy to use and come in a convenient little container for simple storage. Just dip these swimming pool test strips into the water wait for the results and adjust everything accordingly. They take the guesswork out of maintaining a pool so there s no need to hire a professional to test the pH of a pool. These strips work well for pools of all sizes from kiddie pools to the backyard and commercial pools. There are enough strips for five tests in a tube.