Tropic Marin's revolutionary new synthetic sea salt which combines maximum purity in terms of its components with the protective and growth-promoting action of bioactive substances naturally found in the sea. They form effective protection for the mucous membranes of the fish whose improved health is clearly reflected in their increased levels of mating and reproduction. Corals respond by displaying even brighter and more vibrant colors. The extent to which both stony and leather corals enlarge and open their polyps is unprecedented. Indications of the improved conditions seen in the corals include greater growth and stronger tissue. They build up reserves which strengthen them and make them less sensitive to unavoidable fluctuations in their environment. At the same time, Bio-Actif Sea Salt encourages the breakdown of pollutants in the water which is evident in the brilliant clarity of the water after every change. Regular use of Bio-Actif Sea Salt maintains optimal conditions over the long term. It is never too early to add Tropic Marin Bio-Actif Sea Salt to your aquarium. If added when the tank is filled for the first time, it will guarantee healthy microbiological development from the outset and the best possible preparation of the water before the aquarium is stocked with fish and corals. This effect is revived and prolonged each time the water is changed. Changing up to 15% of the water on a weekly basis will sustain the quality of the water at a level which is conducive to the well-being of fish, corals, and other invertebrates.