The Seachem CoralCrete is a two-part epoxy putty that can be used to secure coral to rockwork or to fuse rockwork together for more stable foundations in reef aquariums. It has a working time of 5 minutes, giving you plenty of time to work while also quickly securing coral or rock. CoralCrete is ideal for working with larger colonies of branching coral, the majority of large polyp coral, and adhering plating coral to rockwork. When used as directed, CoralCrete is safe for aquarium inhabitants.