Depends on what kind of wood glue you use. Check the label for specific hazards, and whatever glue you end up using, make sure it is completely cured before you put it into the water.
I would use a polyurethane adhesive or two part resin epoxy. I haven't looked at the label for Gorilla Glue but I would guess that it will work fine (although that is just a guess). Again, just make absolute sure it is completely cured before putting it in the tank. Wait 2 days.