Ponds are better in cement than using the black pond liner

I checked on the ponds a little while ago, and even though the cement pond is all cleared out and ready to be cleaned and refilled for the summer, the one that has the black plastic liner thing in it is still filled with ice. The edges are thawed on it, but the ice is too big for me to be able to get it out of the pond. I plan to try breaking it apart to make it maybe melt a little faster, but not sure if that will work or not.

Will definitely be making the rest of the pond system cement instead of black plastic liners. The liner was harder to inset in the ground, is a basic artificial looking shape and has an ugly black color to it. I can make a much nicer looking pond system using the cement method.