Maintaining a balanced, stable pH is vital to the health of aquarium livestock and efficiency of the bio-filter. The pH of an aquarium can fluctuate due to biological and/or chemical activity within the aquarium. Often, the pH of a new system tends to measure at a higher pH value and subsequently drops as the system ages. pH Neutralizer adjusts high and low pH values to a level at which most freshwater community fish and plants thrive and reproduce, 7.0 pH. pH Neutralizer also removes chlorine, chloramine and ammonia.