The Fauna Marin Balling Light Magnesium Mix is a high-quality magnesium supplement designed for saltwater aquariums to maintain the essential magnesium levels required for coral health and growth. This mixture specifically contains magnesium chloride hexahydrate, which helps to replenish magnesium in reef tanks that can deplete over time due to biological processes and water changes. The recommended preparation involves dissolving 2 kilograms of this mix into 4 liters of osmosis water before diluting it further with reverse osmosis (RO) water to a total volume of 5 liters.