Natural White #0 Bio-Activ Live Aragonite Reef Sand is covered with naturally occurring biofilm found in the ocean. The bacteria on the sand are preserved in their natural live state using a patented process with a QX-23 saltwater enrichment solution. Aragonite reduces harmful nitrate, maintains proper pH, enhances buffering capacity and provides essential inorganic elements such as strontium, cobalt, zinc and molybdenum. Ready to instantly start the ammonia cycling process and stabilize inside your saltwater aquarium. This sand is digger friendly, sand sifter safe and suitable for deep sand beds. Size #0 Natural White sand has grain size ranging from 0.1 to 0.5 mm.