You may find that you have more dead and dried out sponges, crabs, snails, etc in all of the many crevices of the rock. You will need to remove as much of this as you can and wash the rock down well. BRS suggests to cure the rock naturally over time, but many people clean it in an acid or vinegar bath to eat away the outer layer of rock, in an attempt to release some of the phosphates. My rock was loaded with phosphates. I did pressure wash the rock and I bleached it, but decided against the acid bath, since the rock is already very fragile. I had the luxury of having a great deal of time to work with, since I am waiting on a Reef Savvy tank. So, the rock has been curing in a Brute container since July. I have run some GFO and changed the water on occasion and finally have my phosphates down to .02. Hopefully will have that down even further by the time my tank arrives.