APIÂ® PROPER pH 7.0 easily sets and holds pH at 7.0 in tropical community aquariums, additionally removing chlorine and neutralizing chloramines to make tap water safe and livable for fish. To boost overall fish health, API PROPER pH 7.0 also provides essential electrolytes, and detoxifies heavy metals in aquarium water. pH is the measure of acidic or alkaline conditions in water, where a value of 7.0 corresponds to a neutral pH, pH values about 7.0 are considered alkaline, and pH values below 7.0 are considered acidic. 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.