Stick with a kind high-speed binder mortar your corals, stones or even overhangs without problems. Longlasting and rock-solid adhesive. Sticks in and outside of the water. Does not harm even sensitive corals. Also well suited for frags.

AquaStik Red Coralline. Underwater Epoxy Putty for marine aquariums and reef aquariums. Color matches coralline algae and live rock. Excellent for securing rock, stony corals, gorgonians and aquatic plants. Non-toxic to fish, plants & small animals. Cures dry, damp, or underwater.