You can, as long as you are positive, I mean really positive, that it is fully cured and has remained healthy on the way to your tank. I do this with rock from my lfs when they have a particularly nice piece. I verify that they have cured it, and I bring it home in my own bucket with tank water in it so that ther eis absolutely no die-off during transport. That may be a little excessive, since I live 10 minutes from my lfs, but better safe than...