wintering a 300 gallon pond

[snazz]

Hi everyone, Nice forum!
I look forward to reading all your informative posts.
I do have a question today though.
I live in Northern Canada with winters getting as low as -45 degrees celcius.
We havea 300 gallon pond 30" deep and we have several large goldfish. Last year we left the fish in the pond year round and they did fine. Although it was a mild winter.
Well this year we brought them into our house and put them in a rather large fishtank. The goal for next winter is to be able to keep them in the pond year round without worrying about having our goldfish die off.
So I am looking for a fully submersible heater that will keep the water warm enough for the fish to stay out there. wether they go into hibernation, or stay active doesnt really matter. Although if tehre is such a product that would do this for us that can run on solar panels it would be awesome!
Do you guys have any suggestions?
Thanks,
Gil

 

[Otter]

You want a pond vent. Basically, this is a floating, insulated box with a metal tube that extends down to warmer water. Because it's insulated and draws some heat from the water, the energy requirements are far lower than for a heater.

There's a popular one called Ice Guard and another one made by Cal Pump. Both can be equipped with 10w lights. At -45° C, though, you may need more than that, though. With such a small pond, a heater might be necessary in an extreme winter just to keep the pond from freezing solid, but you'd need a lot of solar for that. If your pond doesn't freeze too deep, though, the pond vent will allow toxic gasses to escape.

How many goldfish do you have and how big are they?

 

[snazz]

Hi Otter, thank you for your quick response.
We have about 12 Gold fish, the 3 biggest are substantially larger then the rest at 8", 6", and 5".
The winter I mentioned where they survived out there was a winter with about 9' of snow, so the top of the pond was well insulated, I was thinking about perhaps a half inch Styrofoam cover with an airhole and perhaps a 300 watt heater or something.
But, that's why I am here asking you and not leaving myself to my own contraptions, :yellowbounce:
I will do a little research on those two products.

 

[koiguy1969]

an air pump and stone will do the job

 

[koiguy1969]

sorry, i stopped typing and went to the bathroom, came back to an incomplete post(actually i forgot about it for a while too).. an air stone about a foot below the surface and covering the pond in a tarpalene 'tent' should do the job. you dont want to circulate the warmer water on the bottom of the pond. when it gets cold. the water inverts and the warmer water goes to the bottom thats why the fish settle there.