CaribSea Fiji Pink Sand with Aragonite is a high grade sand substrate for use with Marine, Reef and Cichlid Aquariums. The Fiji Pink sand is a pristine ocean sand that helps to create a natural and mineral balance in the aquarium while actively promoting fish health. The sand is collected from perfect ocean waters, and not beaches, and contains no harmful organics or impure chemicals. The reef sand has been precision-graded for enhanced and efficient calcium carbonate buffering. It is high in strontium, magnesium and essential reef elements and is free of silicia. The superior buffering capabilities help to maintain a correct pH level of 8.2 without the constant addition of other chemicals to the water. This creates the perfect enriched water for the life inside. Each pound of Aragonite in the sand provides an impressive 10,000 square inches of surface area for maximum growth of beneficial bacteria. This vital water-purifying bacteria helps to keep a balance of harmful chemicals and controls the likes of Nitrate, Nitrite, Ammonia and harmful waste products in order to keep your fish and tank clean. Specifications Model: CaribSea Fiji Pink Marine Sand Size:15lb/6.8kg Bag Directions: Rinse well with clean water. Do not use soap or detergent. 1 to 2 pounds of sand per gallon of water is usually sufficient for most displays. More exact measurements can be obtained from the manufacturers website. For best results, follow all directions on packaging. When using Aragonite for African cichlids or other freshwater applications, a slight cloudiness may persist until the aquarium cycles due to high rates of calcium carbonate dissolution. Composition: Magnesium - 1,050 ppm Calcium - 381,000 ppm Strontium - 7,390 ppm Grain Size: 0.5 1.5 mm ppm - Parts per million.