pH is the measure of acidic or alkaline conditions of water. 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. Check the pH level using a pH Test Kit. pH UP is designed to raise the pH of aquarium water where testing has shown pH to be at an undesirable level. pH UP raises pH and makes aquarium water more alkaline. pH UP is fast-acting, colorless, easy to use and will not cloud or color the aquarium water. pH UP is phosphate free and nitrate free therefore will not encourage algae growth.