Flexible ponds liners allow you to create a custom pond designed to fit your garden. During fill up, a flexible liner can shift when water puts pressure on the sides of the pond. Shifting increases when slack in liner corners push against the sides of the pond hole. Folding the liner corners reduces liner shift and provides a professional finish to your pond.
Align the flexible pond liner in the pond hole.
Set the end of a water hose in the liner. Turn on the water to fill the liner.
Pull the liner -- sitting in a corner -- toward the centre of a pond to form a crease. Fold the crease over the corner. Set a 450 to 900 g (1 to 2 lb) rock where the lap meets the bottom of the pond. Move to another corner and create another crease. Crease each corner of the liner.
Move around the liner, pressing the lapped liner corners against the sides of the pond. Ensure the liner does not pull down into the pond hole as you work the liner into position. Turn off the water and reposition the liner if it begins to pull below the top of the pond hole.
Turn off the water when it reaches its final height.