CaribSea Aragonite Products Nobody puts as much effort into bringing you the quality and selection of aragonite products as CaribSea does, All of our substrates are scientifically sound and proven products, Aragonite, purposely engineered and free of impurities such as ash, metals, pesticides, and silica; allows you to create a safe and beautiful environment for your fish and invertebrates, Why take chances with other brands? Fiji Pink Reef Sand - This is a good intermediate sand size product, The precise 0, 5 - 1, 5 mm grain size combines some of the animal friendly properties of fine sand such as ingestibility and low resistance to burrowing, with better diffusive flux properties and good porosity, 15 lbs, SKU: RYLHC1136