This live sand utilizes Sea Breathe laser technology which preserves real live sand with its own original bacteria. Every grain of Ocean Direct is coated with bacteria and encapsulated by capillary action in a thin film of real ocean water that is open to the atmosphere for unparalleled gas exchange. Every breathable bag of Ocean Direct is alive with up to 1000 times more beneficial bacteria than other preservation methods. Each bag includes a packet of Bio-Magnet clarifier to reposition free-floating bacteria to where they are most active; sand beds, live rock surfaces, and to biological filtration media. Ocean Direct provides a thriving, natural aquarium in minutes! The 20 pound bag of Ocean Direct Live Oolite has a typical grain size between 0.25 mm and 1.0 mm and features an average density of 96 pounds per cubic foot.