Nature's Ocean Bio-Activ Live Aragonite Live Reef Substrate 16LBS Premium Live Aragonite Reef Sand for Aquariums Collected in its natural environment and packaged in its natural state (U.S. Patent #'s:6,376,299 & 6,939,708) Just place in tank, add saltwater (for best results use NutriSeawater) then add fish, no waiting required. Instant ammonia cycling Perfect for most applications (except Undergravel filters) Reduces algae growth