Water Gardening: Help: winterizing tiny plastic pond with resident frog!, 2 by Cheryl_103

Cheryl_103 wrote:
Early this summer, we installed a small pre-formed plastic pond (3 ft. x 2 ft. x 18" deep at the deepest) in a raised garden. It's got a small pump without filter for a pump-style fountain. See photos.
The plants are two potted swamp milkweed. A frog I believe to be a green frog (species, not color) has been quite happily living in the pond since late August or early September.
We're sure this plastic pond would freeze and crack over winter, especially since we're supposed to be in for another bad one here in Pittsburgh this year. Last year we had a long stretch of single-digit temp days.
We put the pond in hoping to encourage local toads to flourish, but weren't expecting a frog. Not sure where he came from, but would like to be sure he can survive the winter.
Any advice would be appreciated, thanks in advance!