Hi guys.

I know for sure that you have to have a deeper pond in order for them to survive. I'm in Canada, and our winters are long and cold. A friend of mine had a pond in her backyard and it was deep enough that the layer of ice on the top only froze a couple of inches. I think it was just over 2 feet. They can survive a cold winter in a pond no problem.

The first year my friend had it she thought she would need a heater as well, but couldn't find one. She was told at the time they'd be ok without one. I don't know if they actually exist, or where you would get one. If that doesn't work, I'm sure you could set up a small heating system from like a hot tub company, or something along those lines.