Silicone

[rayjay]

I couldn't find any that said aquarium use when I was at Home Depot, but I got tubes of Rona's own silicone that used to say it was good for aquariums but now says it isn't.
It is supposed to be the exact same silicone in the tubes according to Rona, but the disclaimer in this case is a safety measure to avoid litigation according to the salesperson.
I've used it to repair and reseal 3 tanks in the last year since the wording was changed and have had no problems to date.
Many brands of silicone are not suitable though, like GE II which has something added that can kill off tank inhabitants I've been told.