You may want to check the calibration of your thermometer in a glass of ice
water. The bottom of the pond should be nearer 39 degrees at this time of
year, or possibly even warmer. Ground temperature should be heating the
bottom of the pond, some.
--
RichToyBox
http://www.geocities.com/richtoybox/pondintro.html

"Scott M." wrote in message
...
I have a pond that is around 3 1/2 feet deep. Right now, my thermometer
indicates that it is 0.1 degrees Celcius down there at the bottom. The Koi
and Goldfish
are still alive but isn't that a little too cold? It's not even winter
yet.
I have a bubbler to keep the surface clear and a floating 1250 Watt heater
if I need it later, but I was thinking of lowering a low wattage heater to
the bottom of the pond just to make sure the poor fish don't freeze. Is
this
a good idea?

BTW, my pond photos are at
http://pg.photos.yahoo.com/ph/murchi...mK9ICBHtrk1kvG

Scott