How do I add a mystery snail to my goldfish aquarium?

I don't want ot upset the goldfish or the snail, so I was wondering how I should do this. Do I need to isolate the sanil to make sure it is not sick or anything? If so, how long.|||Pfft. The goldfish won't eat the snail. The snail will duck into its shell and close the door if the fish bothers it. Just pick up the snail gently and drop it into the water. There are a couple of fish diseases that snails can be intermediate hosts for, but if the snail has one, quarantining it isn't going to help. If you got the snail from a reputable source, it should be fine and not hurt your goldfish.|||Well, as Ghost Shrimp fan said, isolating will not help. I found a snail in my tank today that came off a plant i got at the pet store I work at. I've known fish to pick off small snails and eat them but goldfish should be fine depending of the size of the snail. I found a rather small one in my tank that has been in there at least a week and my Danio's havent made it a snack yet. If you're overly catious then I suggest not doing it, but it should be fine!|||The goldfish will undoubtably eat the snail :( but you can try. Good luck!