coldwater fish tank/outdoor pond

Question
I have a fancy goldfish with a double tail which has outgrown 2 tanks, he is approx 20cm. I have had him for 2 years and he is my only remaining fish.  
I do not want to buy yet another tank, would he survive in an outdoor pond that my neighbour has which has over 100 fish in it.

Answer
Hey Brucol,

the goldfish will survive in a tank he's "out grown" for a while if you plan to save up for a bigger tank. if you dont plan to get a bigger tank any time soon, the pond may be better. test the pond water and make sure it's safe first, also if it has 100 fish, and it's less then 750 gallons, your goldfish will suffer. get an estimate as to how big the pond is, and make your best assumptions based on that info. if you feel its better then a small tank, go for it, he'll be fine... so long as a wild animal doesnt eat him.

hope this helps out! best wishes