I've used clear silicon, the kind that comes in a tube, for fishtank decorations before. Just picked it up at the hardware store. It stinks to high heaven but it works fine once its cured. You can't actually use it underwater, it has to be out and dry for awhile and then you can put it in.
There's also the stuff that salties use to put their stuff together...shoot I'm not remembering what its called. |