Check online for a used tank, craigslist is usually loaded with them. You need a larger tank and filter NOW. This is exactly why it is best to stock a tank with fish that will never out grow it. We never know what life is going to throw at us. We may intend to get a bigger tank later, but often times later is too late. If you can't find a good used one, start looking to rehome them in a suitable environment. It's tough, but it's best for them.
The pond could work, however it depends on what kind of goldies they have. If they have other double tail goldfish, then it probably will. If all of their goldfish have single tails yours wouldn't make it. Fact is double tail gold fish are slow swimmers compared to single tails. That mixed with them being very weak right now, they wouldn't make it.
The pond could work, however it depends on what kind of goldies they have. If they have other double tail goldfish, then it probably will. If all of their goldfish have single tails yours wouldn't make it. Fact is double tail gold fish are slow swimmers compared to single tails. That mixed with them being very weak right now, they wouldn't make it.