liferock shapes is made of an aragonitic base rock, instead of the typical cement used by some other artificial rock creators. every rock contains a network of micro and macro pores that intertwine within the rocks internal structure, creating the perfect environment for natural nitrifying bacteria. liferock is manmade. every liferock from has an artificial coating and texture that mimics natural coralline algae after being in the ocean for years. Features. Liferock shapesSpecifications. Weight 20 lbs