Beautiful MarcoRocks Bahama Aragonite reef sand is 100% natural.
One 22.5 lb. bag will fill 2 square feet to a roughly 1.75" depth.
MarcoRock's unique blend of grain sizes is specially formulated to give you the benefits of an anaerobic zone in less substrate depth than other sugar size sand grains. The mix of some slightly larger size grains aids to hold the substrate in place during strong currents.
For best results, rinse prior to placement in the aquarium. Although not biologically necessary, this rinse will help to minimize clouding. Clouding is not harmful. Fine particles are calcium carbonate and will actually buffer the Calcium and pH. Any clouding usually goes away once it takes on bacteria in the water column.