The Fauna Marin Elementals Trace Cobalt (Co) is a highly concentrated solution designed to address cobalt deficiencies in reef aquariums, ensuring optimal coral health and growth. This product contains high purity organic and inorganic cobalt compounds that are essential for the synthesis of vitamin B12 within corals and other marine organisms. Each 250ml bottle provides precise dosing at a rate of 1ml per 100 liters (26 US gallons), adding 4 micrograms of Cobalt per liter, making it easy to maintain stable cobalt levels in your reef tank.