Well, the last evening of sub zero temperature killed off my water butts. I came home to find them both split along the bottom and up the sides. I now think that I should have emptied them. Good new though, now it is thawing I can see my carp survived in the pond. I left the pump and filter going and he seemed to have survived by staying in the movement of water between them. I do hope you all had a great time over the last few days. Here here to a great New Year.