BUILDING THE PREFORMED POND
3. Set the pond. As you continue to build your Koi pond, place the rigid or preformed liner into the hole and check the height of the Koi pond's rim. The rim should be approximately 1 inch 
above the ground to prevent any runoff from going into the pond. You can add or remove the soil from the hole's bottom until you achieve the desired height.
Build your pond the easy way! The pond kit shown at left has everything you need to build your pond. This preformed foldable pond liner system will let you enjoy the convenience of a preformed pond AND the flexibility of a PVC liner. It is available in many popular pond designs and its included pond underlayment doubles as a convenient pond template.
4. Level your Koi pond. When building a Koi pond with a preformed or rigid liner you must make sure it is level. Place a 2x4 across the pond and use a spirit level to check it. Continue doing this in several places around your pond until it is level on all sides. Before adding any water, make sure your Koi pond is level! With even a few inches of water in your Koi pond's preformed shell, it will be virtually impossible to move, so level your pond first. Once it is level you can start slowly filling it with water. As the water begins to rise, fill the hole around your koi pond with sand or sifted dirt. You can use the handle of your shovel or the end of a 2x4 to 
gently tap the soil as you put it in. Continue building your pond and be sure to fill any gaps or holes, especially around the shelves. Frequently check the rim of your Koi pond to make sure it is level. Also, as you build, do not let the water level inside your pond rise above the dirt around the outside of the rim. This could cause your preformed or rigid pond liner to bulge outward. When building your pond consider adding a fountian. The exotic water dispaly is a feast for the senses. This beautiful water garden focal point is sure to be a conversation piece for your guests. The fountain spray also aerates water beneficial to all pond fish.
5. Add your edging. The final step in building your preformed Koi pond is concealing its edges. Once you have filled your pond with water you can conceal the rim with rocks, or flagstones. If you do use flagstones, do not allow their full weight to rest on your pond's rim. 
The weight may deform or damage your Koi pond's walls. When I built my first pond I simply laid the rocks on the edges of my pond, but you can embed them in a 3-to-4-inch bed of mortar, if you wish. Create a calm oasis with the rock cascade shown at left. This artificial rock is a beautiful lightweight enhancement to any pond and is a great alternative to bulky landscaping rocks. Installing a cascading water feature to your pond is now easier than ever with realistic preformed rock formations. A pond waterfall combo kit is also available