It is a very light weight rock from the Pacific. It`s popular for building reefs due to it`s light weight and high capacity for bacteria growth. It has very dark purples and some orange coraline algae growths. Each rock is going to be about 3 to 11 inches. Live Rock provides the foundation of a reef aquarium. Biological filtration, structure and beauty. This is a porous rock. Usually, 1 to 1.5 pounds per gallon is recommended. Our Premium Fiji Rock will require a 2-3 week curing process. Not recommended to place in a fully cycled tank.