[Year-round Outdoor Pond/Tub Seattle]

Has anyone tried keeping medaka in Seattle in outdoor tubs year-round? I was thinking about starting a 20-gal patio pond and adding a heater during winter months. 

On another note, I was thinking about adding my Ameca splendens colony to my 50-gal rain barrel outdoors and adding a heater during winter months. Has anyone tried keeping A. splendens or similar goodeid species outdoors?

[New fish from local auction]

Any A. splendens fry yet? mine put out about a dozen after one month