Toxic substances such as chlorine and heavy metals can get into the aquarium water with every water change. Even our well monitored drinking water often contains such substances in concentrations critical for fish and other aquarium inhabitants. sera aquatan immediately conditions tap water into fish friendly, healthy aquarium water. It removes harmful substances such as chlorine and chloramines, binds heavy metals (e.g. copper, zinc or lead) and protects against ammonia. At the same time, it adds important mineral substances in a bioavailable form to the aquarium water, which is to the benefit of fish, plants, invertebrates and useful micro organisms. Calcium for a strong, well proportioned skeleton and flawless scales Magnesium for strong growth and muscles Manganese for healthy growth and improved fertility Iodine for a balanced development and better disease resistance aquatan thus ensures optimal living conditions for all aquarium inhabitants.