Neutral Regulator adjusts pH to neutral (pH 7.0) from either a low or high pH and maintains it there. It softens water by precipitating calcium and magnesium while removing any chlorine, chloramine, or ammonia. DIRECTIONS: Use 1 level teaspoon for every 40-80 L (10-20 gallons*) once or twice a month (or as necessary to maintain a pH of 7.0.) Neutral Regulator may be added directly to the aquarium at any time. Ideally, it should be used when adding or changing water by dissolving in the replacement water. Info from SeaChem