Thank you Victor, I agree with most of what you had to say, and I am not claiming to be an expert on Koy. One big detail that i failed to mention is pond depth and design like you commented on. I suppose one reason i am able to leave the water running year round is that I have a large area that is circulated very little and stays much warmer than the rest of the pond.
One other thing to consider though is that Nashville's avg tems from Jan 1 - Feb 28th is 29/50 compared to Columbus which is about 20/35 according to weatherunderground.com
Kevjenty, you certainly wont go wrong doing what Victor has suggested, I was just saying i dont think it is needed. If you are unsure go with Victor.