This year for the first time I had some fish outside in a water garden,they are 12 of the most charming feeder goldfish you have ever seen. They did quite well and I want to keep them over winter but I am unsure how to. Should I buy an aquarium or just keep them in a wash tub, and how big of a space do they need? Also I would like to keep the plants that are in the garden, can I leave these in the tank as well? Just curious, Shelley.