Pretty much any of the "super-glues" work well, some people prefer the gel style,,,i get mine from
Premium Aquatics,,they carry a "coral glue" that works well and lasts a long time,,,i've noticed , (unless you use it all at once) that the lil tubes tend to dry out, by the next time you use them,,
the stuff that Premium carries is prob plain ol super glue, but the fact that it works for me, lasts/stays "good" for a long time,and the price ($8-9, i think) is much more economical over the lil store bought tubes IMO
Oh, almost forgot,,,, from what i seen/read/heard ,super glue is fine in a tank, as soon as it holds to what you are gluing,,,you can put it in the tank , no worries,,,
