Koi

Block-built ponds are the Rolls Royce of Koi ponds, due to the variety of shapes and sizes available, their shear ruggedness and longevity. However, the high costs and specialist skills required to complete these ponds tends to limit their application to more experienced Koi keepers.

Once the hole has been excavated, the first step in constructing a block-built pond is to install a concrete slab as the base, before the walls are built from standard pierced concrete blocks. Many ponds require the installation of reinforcing steel rods to stabilise the physical structure of this concrete shell.

Many Koi keepers choose to line the concrete shell with a box-welded liner or seal it with a waterproof sealant, many regard sealing or skimming the surface of the shell with hard-wearing fibreglass as the ultimate Koi pond. While a fibreglass skim does provide a hard-wearing surface, it can prove to be an expensive process and almost certainly requires the services of an experienced contractor to achieve an acceptable finish.

The rigid concrete shell provides a stable framework for the installation of any pipework or drains. However, obtaining a watertight seal around any intrusions into this concrete shell can be tricky. Unlike liner ponds, installing new drains or fittings into a block-built pond can be very difficult and is always best avoided by a undertaking a thorough planning process before the construction is started.
 

Written by Craig Baldwin

Photo courtesy of Simon Kelly