Select a location on your property where the ground is fairly even and the pond will get a minimum of 6 hours of sunlight per day. It is best not to place the pond directly under trees, since falling leaves can foul the water and the tree roots will make digging difficult. Free form your pond in any design you choose, using a heavy garden hose or a heavy rope to lay out your design.
Using a level, at least 36" deep sloping the bottom from 24" and keeping the sides straight (90 degrees to the surface) to discourage predators. A concrete shelf, 4" to 12" deep can be included around the edge to be used for plants and to keep the edge from collapsing in wet weather. A bottom drain should be installed at the lowest point inside the pond. If you include a waterfall, it should be at the shallow end. See also: How to install a bottom drain in a flexible liner& "The Art of Building Waterfalls"
Materials such as sand or carpet padding are typically used used to line the excavation site. A 3" bed of fill sand can be used on the floor of the excavated site for padding and protection of the liner floor.
Place your flexible liner into the pond with at least 18 inches of liner lying outside the edge of the pond. Folding the portion of the liner which is inside the pond and taping it with liner tape will give a neater appearance. You will need additional liner under the waterfall to act as a bib.
Add a rock border around your pond, allowing the rocks to overlap the pond edge by 1" to 2". The excess liner can be tucked under the border rocks or trimmed. Be sure to allow excess if you trim, since your pond will settle.
Install filtration and a pump for a waterfall. Treat your pond water with AquaSafe pond formula. Add plants, wait several days, then add a few fish. Add the balance of your fish gradually over a 60 day period. This will ensure that your pond and filter are biologically ready to support aquatic life. Fish are best fed in the morning, and only the amount they can consume in a few minutes. See Aqua Art pages on nutrition & feeding.