A Guide to Modern Koi Pond Construction

Mid-water pipework

With the feed from the bottom drain to the vortex chamber then it is not necessary to have a mid-water feed. However, with an unheated pond some koi-keepers prefer to have the option of being able to use a mid-water feed during the worst of the winter months when the fish are lying on the bottom.

This photograph shows a 4" pipe laid in position whilst building the walls. The wall at the back is part of the filter chamber.
The long length of pipe inside the pond will then be cut off leaving just a short stub of pipe which can be used to hold a grid to prevent the fish from being sucked in.

This pond will be rendered and fibreglassed, but if you intend to use a liner then you will require the necessary fitting to go through the liner.

If you use the mid-water system then solids such as leaves etc will still accumulate in the bottom drains, and you will need to flush out the bottom drains at regular intervals. It will also be necessary to vacuum the bottom of the pond.

We will now look at building the walls.