Different fish need different pH levels to be healthy, so it is important to test your water regularly to ensure pH levels fall where they should. If water does not test at the desired pH level, use API PROPER pH 7.0 to adjust and hold the level. API PROPER pH 7.0 works best for communities of tropical fish, and should be used when setting up an aquarium, or when performing a water change. Do not use in aquariums containing live plants. Safety Information Please Read Instructions Before Use Directions Add 1 scoop for every 10 gallons of aquarium water. Repeat dose when pH test indicates a pH change of more than 0.2.