PVC Pond Liner

https://www.dlmplastics.com/store/Pond-Liners-c8574666

Use this calculator to get price: https://www.dlmplastics.com/quote (

a liner for our pond - 6 wide, 4 deep, 20 long - would be 18 ft x 32 ft)

And also

https://billboardtarps.com/product-category/pond-liners/

The price per sq ft is at the bottom of this page: https://billboardtarps.com/custom-large-sizes/