Easily ensure that your pool or hot tub's chemical levels are right where they need to be with the Bestway Pool & Spa 3-in-1 Chemical Test Strips. These strips are the ideal solution for chemical testing because they instantly show the free chlorine, pH and total alkalinity levels in the water. Once dipped in the water, the strip will turn a different color. Use the easy color-match system on the side of the bottle to quickly and easily see the level of each type of chemical present in the water. The Bestway Pool & Spa 3-in-1 Chemical Test Strips have an 18-month shelf life, so you can keep them on-hand to use as needed.