will the snails eat algae off of plants and rocks too? and they wont bring any diseases with, will they?
i am interested in the snails as opposed to an additional fish, because truly this tank is about my goldfish. And to allow them fifteen gallons just the two of them, would be ideal.
Do snails count in the one-inch-per-inch-of-fish rule too?

Luckily my cousin is in need of a pleco and has a huge tank, so Frank will soon be given to her. I feel more comfortable with that than returning him to the store - he would probably die if i did that.