eventually, it all becomes "live". if you're looking for a DSB, go with a 4-6"aragonite substrate. you can always go barebottom too. best place to get it is at your LFS. and not the stuff in the bag, but if they have a tank full of live sand, get that stuff. or, you can buy from someone who is breaking down their tank. if you have no other choice (as someone on here just posted) get it out of the bag.