CaribSea's Reef Forest Kit provides a variety of LifeRock pieces and building rods to create an aquascape of your dreams. The base, 3 arches, and 3 spacers stack quickly to give a three-dimensional design with plenty of negative space and a large surface area for corals and other inverts. Easily set up something incredible in minutes with no cements or glue, being modular allows for easy separation of corals and re-scaping as needed. LifeRock is infused with spored bacteria for biological performance, creating a mature looking reef instantly and is 100% safe for all marine animals. Made of aragonitic base rock, this environmentally friendly option contains micro and macro passageways for natural nitrifying bacteria.