BRS Pharma Magnesium Chloride, available in a convenient 7 lbs jar, offers ultra-pure magnesium additive for your reef tank. When used in conjunction with BRS Pharma Magnesium Sulfate, it helps maintain proper magnesium levels, achieving the essential balance of calcium and alkalinity in your tank by preventing excess calcium carbonate precipitation. Unlike traditional magnesium chloride additives, when dissolved with BRS Magnesium Sulfate, it dissolves crystal clear with no undissolved salts or residue left behind. Crafted from pharmaceutical-grade materials, this magnesium chloride from Bulk Reef Supply is designed for easy dosing, mixing fast and clear, and leaves no residue behind, ensuring optimal reef health and growth. Plus, buying in bulk allows you to save money, and the resealable packaging ensures freshness and convenience.