most people will tell you that it doesn't matter if cured or uncured--you still have to isolate it at home to deal with any die-off from shipping. We put our 30# (from another site actually) in an old 20 gal we had with a heater, powerhead and a small cheap filter ( some say skip the filter) for about two weeks. We continuously moved the rock around to get good circulation and wire brushed some areas that looked dead (white spots) We went through a few water changes in those two weeks, at one point the water was smelly (die-off) and the water was quite cloudy when the rock was moved around. So we were glad to wait--didnt want crud in the good tank. When the ammonia was down, we moved it in a little at a time. Seems like everything went fine. Our fish weren't disturbed. We are however, still rearranging the rock! hard to get it just right!HTH