Thank you, our contractor friend built it for me. I was worried about top rail having chemicals if we used pressure treated so he came up with using Trex on the outside. Its insulated between the liner and wood frame. Here is a pic of what I had before.
Pond looks great. It always amazes me when people successfully keep fish in the rubbermaid troughs. My sister works for rubbermaid and says that the troughs should not be used for fish as they do have chemicals in them that can leech into the water and kill the fish. I am starting to wonder if rubbermaid knows what they are talking about though as I have seen MANY people use them for this