A mirror pond is a unique eye-catcher in your garden, but building a mirror pond requires some precision. The reflection of the water is of course what it's all about and you only create that with the cleanest water. If you are going to build a reflection pond, first realize that the substrate of the pond must be stable. In addition, a mirror pond requires an extremely smooth surface: otherwise, of course, the pond cannot mirror. So the pond liner must also be laid tightly. Since a reflecting pond is obviously meant to be primarily decorative, the tighter the edges slope downward, the better. Finally, a reflecting pond looks best when you lay a long side and a short side, with sharp corners.