I just picked two of the real wooden ones up today at Lowes for $30 each. One is going to house the filter media for our pond we already have and I want to make a little dirted pond out of the other one. Question though. I know they make preformed drop in liners, but from what I see online they cost more than the barrels did. What's the best way to line them with a regular liner? I imagine you'd end with with a lot of wrinkles and a not very pretty looking edge.