Starting your first saltwater reef aquarium with live rock or live sand will help to shorten the time needed for your tank to re-cycle properly. This is because the life rocks and live sand will create a perfect environment for the nitrifying bacteria to grow and thrive. Life rocks are basically calcium carbonate remains of dead corals and other calcareous sea creatures. Before choosing your live rocks, it is important that you have already decided on your saltwater reef aquarium theme first. This is because live rock from different oceans will have a different kind of coralline algae that grows on it and each coralline algae will have their own unique color. For more information about live rock and live sand, click on the link.