API pH Aquarium Measures Test Strips - Wide Range Saltwater Dip & Read 25 Tests Contains one (1) API pH TEST STRIPS Freshwater and Saltwater Aquarium Water test strips 25-Count Box. Monitors water quality and prevents pH problems that can be harmful to fish. Dip test strips into aquarium water and check colours for fast and accurate results. Helps eliminate fish stress caused by incorrect pH levels in freshwater and saltwater aquariums. Use for weekly monitoring and when water or fish problems appear. It’s Smart To Be Proactive! The best way to keep your aquarium clean is to maintain good water quality. This will keep your fish strong and vibrant, as well as preventing disease. How Do I Maintain A Healthy Environment? It is important to test your aquarium water weekly to verify good quality in addition to a bi-weekly partial water change of no more than 25% to help reduce toxic buildup, remove debris the filter missed, and replenish the oxygen.