Live sand, or
LS is natural reef coral sand that is collected live from the ocean, or non-living coral sand that is cultured to make it live. What makes it live is the microscopic biological bacteria that grows on it, and the many tiny crustaceans and other micro and macro-organisms that reside in it. Live sand can serve as the main base for biological filtration in a saltwater aquarium, while the organisms help consume organic matter in the sand bed. Some of the organisms provide a natural food source for many aquarium inhabitants as well.
What Type to Use?
There are many types of sand to choose from on the market, but sand of coral origin, such as coral sand, reef sand, crushed coral, or aragonite are best. One top choice of many expert aquarists is aragonite by CaribSea. Sand sources other than aragonite types will most likely have silicates in them, which is something you do not want in your aquarium. Silicates cause algae problems, and once introduced are next to impossible to remove.
There a three basic choices for starting an aquarium with live sand:
You can use 100%
LS, which can be very costly.
You can use a 50/50 combination of
LS (bought or used from an already established aquarium) with non-living sand. By mixing the two together (seeding) you save money, and the
LS will convert the non-living portion of the sand into
LS over a shortened period of time as the biological bacteria and the living organisms multiply and populate it.
You can use nothing but non-living sand, as all sand eventually becomes live over time. However, starting from scratch does take much longer for the cylcing process to complete its task.
HTH