Attaching halved pieces of live rock

[sbreefer]

I have been attaching halved pieces of live rock to the back of my tank that I sawed with a 14" dimond saw. The goal is to get me a little more depth the the sps to grow out. The look is great, but they dont want to stay. I have tried epoxy putty. Any suggestions on adhesive that is safe for existing inhabitants as I am doing more.

 

[OldNemo]

What about gluing magnets to the rock and attaching it that way? Or do you run into the same issue?

I've never used it by super glue gel (cyanoacrylate super glue) is evidently reef safe. I've read a few post in the past regarding the same. GL