Koi Pond Construction

The first step in koi pond construction is to mark out the parameters. This can be done with orange paint or stakes.

	3000 Gallon Koi Pond Layout
	Outside dimensions:16'X21 Coping shelf: 4"-6" deep 8"-16" wide Shallow area: 10"-12" deep Mid level:16"-20" deep Deep Level:24"-30" deep

 

You can also mark out any shelves where you can put shallow water plants and bolder rocks. Remember that any large rocks you plan to put in the pond where the bottom of the rock is going to be below the water level needs to be placed on top of the liner. There is no way to seal liner materiel to the rock that will prevent a leak. The same holds true for the water fall.

Dig out the shallow areas first. Use a line level to determine the water level.

Next mark and dig out the mid level and where the skimmer will be located.

Next mark and dig the deep level and finish excavation of the skimmer hole.

This is a typical view of designing the koi pond for plants.

Shelves should slope back to the bank to help keep the rocks in place. Remember that koi like to sift through the gravel. Sloping the ledge toward to deeper part will not hold the gravel.

You can see in the drawing above how the ledge is sloped to hold rocks and gravel. This also makes a semi barrier to keep koi away from plants they can destroy. Plants can be planted directly in the gravel. They will make their own soil over time.

The drawing below shows a typical skimmer and water flow layout.

Typical skimmer installation

Place the skimmer at the proper depth where the maximum water level will be about one inch below the top of the weir (inlet door) and level. Now it is time to run the plumbing. I normally use 1 1/2 inch pvc pipe for the plumbing, since this is the outlet size of most pond pumps. The pump is mounted in the bottom of the skimmer. Use a true union at the pump so it can be taken out for yearly cleaning without having to cut the pipe. Dig a trench at the bottom of the pond for the pipe. This will keep it from freezing in the winter. Once the plumbing is in place fill the trench with dirt. A layer of sand can be added to the bottom to help protect the liner. Dampen the sand to make it easier to work with and help hold it in place when installing the liner.

When installing the liner allow at least a foot to cover the bank. It is a good idea to fill the pond after installing the liner to check water for leaks and water flow before adding the gravel and rocks. You may find areas where the water is too shallow or the water runs over the side. It is easier to correct these problems before adding gravel and rocks. Make sure to allow for the dirt to settle if you had to add fill dirt. Now it's time to add the gravel and rocks. I typically use river gravel for the bottom surfaces. It is best to rinse the gravel before adding it to the pond.When placing large rocks in the pond it is a good idea to cut a piece of liner to place where to rock will be set for added protection. You may even want to put another piece under the liner if the rock is really big.

Before purchasing plants or fish add a good water conditioner to the water to remove chlorine and heavy metals. Run for about 1 week before adding fish. When the fish are added is a good time to add a good bacteria starter, that can be purchased from your local pond supply or pet store. Another good additive is koi clay which is a mixture of calcium bentonite and montmorillonite clay powder. This will help the water clarity and is beneficial for the koi.