Here are some underwater epoxy products.
AquaStik Putty - Stone Grey - 4 oz.
The AquaStik Stone Grey Epoxy works on dry, damp, or wet surfaces and cures underwater. AquaStik is non-toxic to fish, invertebrates, aquatic plants, reptiles and small animals. It is excellent for attaching live rock, stony corals, gorgonians, aquatic plants, and other aquascaping items. It also bonds to wood, concrete, ceramics, acrylic, metals, and fiberglass. Aquastik can be drilled, sanded, sawed, and machined and is useful for making repairs.
AquaStik is hand kneadable and fast curing. It has no strong oder. It mixes in minutes and hardens in 20 minutes. It is at full strength cure in 24 hours. The stick format eliminates waste or mis-proportioning. The clay-like consistency affords no-mess application requiring no tools. It can be used in marine and freshwater aquariums, ponds, reptile and small animal habitats.
Aqua Stick Putty for Marine Reefs - Red - 2 oz.
Help those corals get a grip in your tank. Use Aquastick red putty to secure your reef specimins to live rock. Red color looks like beautiful corraline algae. Excellent for securing rock, stony corals, gorgonians and aquatic plants. Non-toxic to fish, plants & small animals. Cures dry, damp, or underwater.