I have some dry Marco rock and the pieces I have for an aquascape that I like a lot. My concern is coraline. I don't think I have ever seen Marco rock encrusted in coraline the way my fiji (I think) rock is. I have a small chunk of TB rock in my tank now as well and that doesn't seem like the coraline takes to it too well either. When I put the fiji in my tank after it cycled it was completely colorless, within a couple months it was completely encrusted in purple. I really want to use this rock but am afraid it wont color up nice.