When I use super glue gel, my skimmer will produce lots of micro bubbles, but not as bad as the epoxy
As for what I use...mostly I use superglue gell, but in some applications I use both the gell and the epoxy. In a real craggy area, where you can't get alot of surface area contact with the frag
and the rock, I'll attatch the epoxy to the frag
with SGG and another layer of SGG on the other side of the epoxy and them press it in, the epoxy will fill in the craggy areas and the glue bonds pretty quickly.