I know you've probably heard it before, but I feel that Tropicorium has the best rock. Even though it is a little pricey, it's well worth it. It has lots of character and lots of holes to plug frags into. Also, it comes with TONS of life. When I bought mine I had a brittle star, tons of abalone snails, caulerpa, little mini-stars, lots of copepods, some coral polyps, etc. I think it's well worth it. Also, the more you buy, the cheaper it becomes per pound.