Use the api ph test strips as a quick and accurate way to test ph levels in your water. These test strips measure a wide range of ph, from 6.0 to 9.0 ppm, to help you keep aquarium conditions safe for your fish. Product comes with desiccant lined tube with snap tight cap, highly precise color chart for accurate water parameter readings, and information on how to correct unsafe water conditions. For use in fresh and saltwater aquariums. 25 count Api ph test strips exclusively test ph levels from 6.0 to 9.0 in freshwater and saltwater aquariums. Both api products will alert you if your ph is too high or low, enabling you to take the proper steps for correction.