SeaChem Reef Builder - 300 g is designed to support clean, balanced aquarium water. Reef Builder raises carbonate alkalinity without immediately impacting on pH. With long term use there will be a tendency to stabilize at pH 8.3. Used as directed, Reef Builder will not deplete calcium, magnesium, or strontium which usually tend to precipitate with increasing alkalinity. Reef Builder and Reef Buffer may be used together. Shop SeaChem aquarium water conditioners at Uncle Bill's Pet Centers for trusted pet supplies and knowledgeable service in Indiana.