Building Costs of a Koi Pond

This is where the wheels can really fall off.

Koi ponds are permanent concrete structures. Built incorrectly they cannot be easily saved or modified.

It is worth repeating. Built incorrectly they cannot be easily saved or modified.

Except at vast expense and inconvenience.

A Koi pond should be built only once. This is the cheapest way over the longer term. Such a Koi pond is built in a way that will allow future upgrades or modifications to the filter system to be implemented painlessly and with ease. Such a Koi pond will allow changes to the design parameters of turnover rates and return rates seamlessly without fuss. Such a Koi pond will make provision for the future in other words. 

Koi ponds are extraordinarily complex entities in their own right. They are not a modified swimming pool and nor are they an oversized fish tank. Koi ponds have to cater for very different circumstances to either of these because they cater to different animals in varying climatic conditions year round.

A Koi pond can only be as successful as its filtration system. The two are inextricably intertwined with both existing in harmony. The balance between the two is the art of water keeping - get it right and you will have Koi keeping success. Get it wrong and failure will be your partner for many years.


Building costs are limited to materials and labour. Knowing WHAT to build is one half of the required skill set, and knowing how to build it is the other half. The integration between Koi pond and filtration system has to be incorporated from the time the first spade hits the ground and hence a successful Koi pond cannot be made up as you go. The design and plans for a successful Koi pond will always be concluded long before the actual construction takes place.

Materials have to be of the highest possible quality. Pipe, valves and other fittings have to be of the best quality available to last the 20 years the pond is built for. Changing worn valves on a Koi pond can be almost impossible if the wrong thing has been used to begin with. Fixing a broken pipe that has burst because it was cheap, horrible and nasty can be an extraordinarily expensive exercise post fact. Imagine trying to repair a bottom drain pipe that is leaking for instance.


There are other costs associated with building a Koi pond. Excavation. Soil removal. Water provision and supply. Electricity provision and supply (it is strongly urged and encourage that you run a separate earth leakage for the Koi pond), sealing the pond, finishes fro the pond, decking for filters, garden restoration etc. etc.

On average, for a completed Koi pond to the point where you are ready to add fish you can budget on around R6 to R7 per litre as of 2013. The shell construction and filtration costs will account for the bulk of these costs, for that you can roughly budget R4 to R4.5 per litre for the pond and filtration.

The pond in the pictures above is perhaps a case study on how not to build a Koi pond, with all due respect to the parties involved. Details are sketchy for obvious reasons but the pond was built by a swimming pool construction company that were clearly out of their depth. This pond is one we recommended be demolished and built from scratch again - there is nothing we could do to save it. As it is the pond would limp along for a year or two at best before collapsing and killing it's hapless inhabitants.

No doubt someone will have patch a hack type fix onto this pond. However, it will never run properly and the owner will always be fighting it. It will be a source of ongoing frustration and resentment for him and it will cost significant money to run it - a low power solution here is impossible to implement.Long term this pond is doomed - and our opinion is to take the pain now, get it over with and put the correct thing in to begin with.


Koi ponds are not swimming pools. The resemblance between a swimming pool and a Koi pond is about as similar as a penny farthing bicycle is to a thorough bred race horse. One is a dead mechanical tool, the other is a complex living breathing organism.

Koi ponds are generally constructed as a bottom out top in philosophy. Koi ponds are designed around their filtration - in this case filtration can be considered the beating heart and lungs of our race horse. Filtration is not an after thought, it is the single most important aspect of your Koi pond.

Without the correct filtration your Koi pond cannot function. Your filtration is the centre of your Koi pond's universe because it keeps the Koi pond alive.

In other words filtration rules the pond, not the other way around.

Our job is not to build Koi ponds. It is to build filtration that is up to the task at hand of the desired Koi pond and to integrate the two harmoniously.


There are five things you need to keep in mind about your Koi pond that were not considered more than superficially in the above project.

1. You are the one who has to pay for running it.

2. You are the one who has to maintain the filters.

3. The Koi hobby is a long term hobby. Filters need to cope with full grown large fish, not small little Koi that you will be starting off with.

4. The pond should be built around the filtration.

5. Filtration should be easy to access and to maintain.