Clay or glue for rocks?

[ravedood]

I bought some frags on rocks and clay tablets but they always get knocked around in my tank by crabs or snails. Is there a way to make them stick to the big rock they are sitting so they don't get knocked over anymore?

 

[racermike27]

Super glue Gel works for me.

Just put a bead on the bottom of the "plug" and then mush and twist into the spot you want. hole it for a few seconds and you are done. Or you can use expoy, I like the deltec one, the others don't work well for me.