just two part stuff from Lowes....think it's water weld made by jb weld
I actually drill holes to my live rock and good enough to fit frag plug and works well without using any glue or anything,in time,it will just encrust the live rock.
i snip off extension on the plug, then squirt some superglue on the bottom of the plug, then press on some epoxy, followed by another squirt of superglue on the epoxy, then press the whole works onto the liverock in the tank. Works great. Using just epoxy or just superglue doesn't work nearly as well for me.