Our Fuji Sponge Ecoscape rock is not only an artistic choice for the home aquarium, but also a safe choice for both fish and plants. Fuji Stone is another rock with an extreme amount of porosity which makes it perfect for nitrifying bacteria and foraging crustaceans such as ornamental shrimp. Its surface also makes it ideal for aquascaping around planted displays—in particular as a base for growing moss. Fuji Sponge is inert and will not alter pH or hardness. It comes in a variety of shapes and sizes handpicked by the Ecoscape team to give your aquarium a unique look.