<a href=showthread.php?s=&postid=14821248#post14821248 target=_blank>Originally posted</a> by SuperOstrich
I use the mix-together aquarium epoxy putty when attaching a rock or ceramic plug. I don't think you want to have the wet glue in your tank. If you could glue the rock to your piece of LR outside of your tank and wait a minute for it to dry, then put the LR back in your tank I'm sure that would be fine. A huge pain in the butt though. I vote for the epoxy. I use Aquastik.
edit: I missed the part where you said it was a REALLY small piece of rock, which makes the putty kind of a pain too. After doing a little research it looks like a lot of people using superglue directly in the tank like you're asking about. I'm always nervous about putting chemicals in my tank like that since I have a nano, so here's my suggestion:
Find a larger piece of rubble rock to super glue your tiny piece of rock to, wait a minute or so, then use the Aquastik to putty that larger piece to your LR. That way the super glue is totally cured before it goes into your tank.