There are several things that come into play:

-Outside temperature
-How protected the pond is (some people build plastic frames to
protect)
-The size of the pond

Out of curiosity, why did you pick 55 degrees? Isn't 40 degrees safe?
At 55 degrees I would imagine their immune system is more intact.



wrote in message ...
I live in Milwaukee. that 500 watt heater is like 5 light bulbs running ALL the time
and the current calculation is @$10/100 watt light bulb per month if they are on all
the time. Given that we heat our garage (gas) and heat our spa (electric) the 500
watt heater doesnt rate. The temperature was set to 55oF. The temp actually went
below 55o on 1-06 (meaning the heater would be on ALL the time) and was above 55oF
2-26. Running a 1500 watt tank heater at the surface of an unprotected/uncovered
pond could easily cost 15- 100 watt light bulbs or $150 per month if it ran all the
time. Ingrid

(MC) wrote:
To keep a pond @ 55 degrees here in Chicago would probably cost around
$150-$200 a month in electricity.

wrote in message ...
piping water out of a pond is always risky business .... the pipe springs a leak and
drains the pond. in winter this is even more likely not to mention the water
freezing in the pipe. second, unless the piping is buried it will chill down on the
return trip and isnt efficient. I dropped a 500 watt heater into my pond, set it to
55oF and my pond stayed above 50 all winter except for one month jan 15-feb 15. my
pond is covered with plastic. Ingrid


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