Pond - half is thawed, half is frozen still

Looking out at the garden area, I can see that the ice in the cement pond has all melted away and the pond is ready to start working on for the year. The pond with the black plastic liner in it, however, is still filled with ice. It will be a few more weeks before I can get out there and get to work on it.

I'm definitely going with cement on the rest of the pond system, since it thaws faster. Also want to get some sealant to waterproof the pond system so it will, hopefully, be less inclined to crack in the winter.