Epoxy, glue?

For those gluing and epoxying stuff in place, what is safe to use? I really need to stop just placing things because stuff keeps falling and getting eaten-not cool! The urchin, clownfish and hermits keep knocking everything around.

I use jb water weld, I get it from menards

I use a ball of epoxy, either the stuff from the fish store or JB water weld or any other stick/putty epoxy. JB is cheaper but most of it is white or light gray whereas the fish store stuff is dark gray and blends in better. I make a ball of it, squish it a little flat and put a couple drops of gel superglue on each side and press it into place. Without the glue the epoxy doesn't stick to rock or coral. Both cure underwater.

I use marine putty that I get from Fleet but I never thought to put superglue on both sides. That would really help cuz you are right about it not sticking to the rock well.

I use the gel super glue, and haven't had trouble with, other than my livestock keeps detaching itself off the glue and wandering away. Brats!