Many people have different opinions on this, but personally, with the amount of money invested, I only buy my glue from my LFS. Why risk thousands over a few dollars.
If its cyanoacrylate it's what we all use. JB water weld, with a dab of super glue on each side is the best way to fix it permanently. Or, go to the lfs; they need the money and of course everything lfs's sell are good for your tank???
Lowes is alright for 10g tubes, but at the dollars you can get 2 2or3g tubes for $1; I've never got bad tubes from Dollar Tree, but sometimes from other stores I have. Again, sg is good for holding frags in place for a little while, but add a ball water weld epoxy ( or the same epoxy with a hobby label for more money) with some sg on each side and things can placed very well for a very long time. There is a bit of cyanide gas produced; for those doing large lr creations it can be dangerous, but beware and try not huffing the stuff.