I take it this preform is surrounded by dirt in the raised bed, right?
drop in a 100 watt submersible aquarium heater set to 55oF
drop in an airstone on a cheap pump.
cover the preform with plastic use a 2x 4 (pine, not treated wood) to hold the
plastic up over the pond. weight down the plastic, or better, use thin wood strips
screwed or stapled down to hold the plastic if you get a lot of wind.
this will keep the GF toasty all winter long. leave on end open. if you have some
kind of in pond filter, keep it running. and drop in a thermometer and continue to
very very very lightly feed the GF all winter when the temp is above 50o.
Ingrid

"SeaRobin" wrote in message
...
I've got a 50 gallon kidney shaped pre-formed pond that's set
into a raised bed about that's about 2ft. high. The pond itself is just
a bit less deep than that.

Can I keep a couple of regular goldfish in there with winter temps
typically at 45-50 F during the day and about 30 F at night? Of course,
we can get temps in the teens and twenties on the odd winter day, but it
wouldn't last long. I have a pump running a bubble fountain that I plan
to remove the fountain head from to make a fatter stream of water just
gurgling up from the pond to make it less freeze prone. Do you think
the fish will survive in such a shallow pond, or should I go invest in
an aquarium and bring them in?


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