I would say that they probably can live together though I don't think it is the best idea. Make sure that you have a lot of room since tinfoils swim a lot as well as the goldfish make a ton of waste. Also, make sure you have a good filter and try and feed them well because the tinfoils may try to nip at the goldfish fins at times. As I said, i wouldn't advise this but you might be able to get away with it, at least for a little while. Once the tinfoils get bigger than they really should be in a tank without goldfish.