Has anyone attempted to build a dog pond in their garden? I will have some help and would love it to be big enough for two large swimmers to swim in and me if I fancy cooling off with them. Do I need a rubber liner over another liner? Im NOT fit for digging or lifting stones/slabs. Approx size I have had is 2m x 2m - can go bigger but not sure how big I need to be! Added pic and needs to be somewhere down left side. I only moved last year so a lot to do.