Surprise, surprise - the plastic waterer sitting on the heat mat was NOT frozen this morning. There was a little 1/2" sliver that froze on the rim for about 4", but that was an area of the waterer that the birds had pushed off the heat mat.
The weather station said we were at 9*F, so I am impressed with this heat mat. I may have to let it sit and see how cold it can get before the water freezes. Maybe not, I don't want to crack the plastic.
The weather station said we were at 9*F, so I am impressed with this heat mat. I may have to let it sit and see how cold it can get before the water freezes. Maybe not, I don't want to crack the plastic.