The rock wasn't always dry. It was live rock set up in my 55 gallon FOWLR system a while back, before I had to move. When I moved, there was no way to keep the water, so the rock dried out, and all the little organisms and things died off and nastified it. Today I'm gonna get some buckets. I already had buckets, but when we moved I had to give them up or storage. But either way, I'm gonna get some salt next time I go to the pet store.