20,000 litre koi carp pond – winter 2025-2026

30/03/2026

20,000 litre koi carp pond – winter 2025-2026

The project was to re-model/replace two existing ponds into a single pond that was to be 5.5 metres in length, 3.2 metres wide and 1.2 metres deep.

The original ponds were constructed by removing approximately 700 mm depth of soil and then a 500 mm high surround of 200 x 100 mm timber sleepers. A similar construction was to be used for the new pond.

The water and inhabitants (23 koi carp of varying sizes) from the original ponds were rehomed in a temporary set up that consisted of an insulated free-standing swimming pool covered by a polytunnel.

This set up was connected to an existing filtration system which kept the koi healthy, through the winter whilst the project was completed.

The new pond was to be constructed with clean lines (a basic rectangle shape) with one long side maintaining the pond plants and vegetation from the original ponds.

This was achieved by Butek Ponds supplying a box welded liner to the pond dimensions with an extended flange of one metre along one length. This extended flange allowed the construction of two planting troughs that could be filled with soil but still connected to main pond to create ideal conditions for the Flag Iris, Horsetail and Sword Plants to thrive.

After deconstruction of the existing pond, excavation of a skips worth of soil and concrete; the new pond surround was created by building a new retaining wall in concrete blocks and extension to the timber sleeper framework. The base and sides were lined with geo membrane ready for the new liner.

Whilst described in just a paragraph, this took about two months of hard work, in between and during the persistent rain of the recent winter.

Installation of the new butyl box liner took a few hours to get in place, ready for slowly filling  over a few days. The filtration systems were reconnected and allowed to run for ten days prior to introducing the koi to their new home.

Butek Ponds were very helpful in working with me whilst I determined the final dimensions of the pond. The supplied 1.0 mm  liner was of the highest quality and competitively priced.