Hey Peg -
Just to add to what others are saying - Remember that live rock always smells. Even if fully cured it will have an odor - just won't make ya want to gag. Some say cured live rock smells like the ocean, ya know, sort of like anything else in our tanks.
Rock that has die off and is not cured will smell really nasty - some say like rotten eggs, but I've not smelled any that bad yet.
When the ammonia and nitrites are no longer present - then you're safe to add it to your tank, and you can assume it's mostly cured.
Smell it then - and you'll see the difference
