posted 12 years ago
I have had a preformed plastic pond for 15 years, and I never empty it. The only thing I do is put a recirculating pump in it in the summer, to keep the water clear (it goes through a biofilter), and to discourage mosquitoes. There is a TON of life in it, I have no idea how all those creatures got there.
The ice won't break your pond - it is plastic, after all!