Dry Live Rock is the most popular hardscape used for natural biological filtration in saltwater aquariums. It is available in two formswet or dry. The store stocks dry rock as its the most eco-friendly option. This dry rock is either human-made or mined from the ground, which means no rock is removed from the ocean. The advantage of dry rock is that it does not host hitchhiking pests and will not need to be cured like most ocean rock.