LS has different meanings to different people. Generally, live sand is just sand that has been populated by the beneficial bacteria that convert ammonia to nitrite to nitrate. Truthfully, real live sand contains all of the bacteria plus various worms and other organisms that populate the sand. LS like you can buy through places like our sponsor contains the various organisms mentioned before. It is collected many miles from shore, in clean water. There are skeptics that say that none of those organisms will survive transit, but it's hard to believe that after seeing what can survive the whole LR ordeal. It is also true that any sand will after time become LS, and some of the organisms from the LR will populate the sand. If you have the money available, order some of the LS from saltwaterfish.com, you really can't go wrong.