This live rock is not cured. It has been freshly collected by our supplier in Florida. If your tank is new without any fish or corals this Rick can be added straight to your tank and will cure in a few weeks. Some of the growth dies during shipping and puts off waste into the water which helps cycle a new tank but if your tank is established we always recommend using a 5 gallon bucket with a pump for circulation to cure the rock for a few weeks . This rock has a good amount of live plants and many other things but the most important is the microscopic bacteria that can't be seen. It is the best biological filter that you can get for a marine aquarium. The right amount of live rock can cycle and establish a new aquarium in just a few months. It will remove ammonia and nitrogen as well as help keep your water crystal clear. We ship the live rock with 2 to 3 day service and almost always smells really bad when received. This does not mean it is dead , it is to be expected. If we have to use the post office you can expect them to be a few days late with delivery but the rock is totally fine in shipping even a week if they are that late. Please feel free to ask any questions that you may have.