SeaChem Replenish - 250 ml is designed to support clean, balanced aquarium water. Replenish™ is a proprietary blend of salts designed to replenish physiologically relevant minerals that are removed by reverse osmosis or deionizing filtration. Replenish™ restores General Hardness (GH) using a balanced blend of both “soft” (sodium, potassium) and “hard” (calcium, magnesium) salts. Restoration of mineral content is essential since a complete lack of minerals will result in osmotic stress in those species whose osmoregulation systems are adapted to a mineralized environment. Severe osmotic stress can result in osmotic shock which will lead to rapid death. Shop SeaChem aquarium water conditioners at Uncle Bill's Pet Centers for trusted pet supplies and knowledgeable service in Indiana.