Florida Live Rock collects only the finest live sand. Since its not an easy job, we only want to spend our time getting the best marine substrate with the most life in it. This aquarium sand comes in from 50 feet of water about 12 miles offshore next to the reef. This has a fine mix off coralline balls, which are pure calcium assorted broken shells and other substrate. In the sand, there is a diverse amount of life such as coppapods, tiny crabs, fish, cerith snails. This is truly LIVE SAND not home made sand. Check out my YouTube Video of some summer sand .