nature's ocean bio activ live aragonite aquarium sand- pink reef sand 20 lb. nature's ocean nature's ocean bio-activ live aragonite samoa pink live sand 20lbs (grain size: 0.5 -1.7mm). premium live aragonite 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) for best results use as follows: use a minimum of 1 pound of bio-activ live aragonite per gallon of saltwater. setup filtering system and allow it to circulate. during the first month, introduce no more than 1 inch of fish per 5 gallon of saltwater. <br> directions: <br> recommended: use a minimum of 1lb bio-activ live argaonite live sand per gallon of saltwater. set up an appropriate filtering system and allow it to circulate. during the first month introduce no more than 1" of fish per 5 gallon saltwater.