Shorty: Thanks! I read: "Maintaining open water all winter in a small pond will have more negative factors than positive." I think that answers my main question. Also, I believe the posts led me towards starting my aerator when the water reaches 45* ~ 50*. For southern Oregon, this is VERY unusual to have ice/snow completely covering the pond, so I am staying alert with being safe, rather than sorry. The blessing is, the Merganzers can't get to my BG now! :p
