The Nature of Successful Koi Keeping - Introduction

"Koi keeping is a peculiar mix of hobby, art, science, and commerce"(Professor Dominique P. Bureau of the University of Guelph)

Filtration on Koi ponds can be a somewhat controversial subject often full of emotion. There are, however, basic principles that apply to all variations of the filter systems hobbyists may encounter. There are basic principles to water keeping that apply to all ponds. By adhering to these basic principles we will successfully maintain the healthy water environment our koi need.

When it comes to “making a plan” the ingenuity of koi keepers and koi dealers never ceases to amaze. Various things have been successfully adapted from other applications for use on Koi ponds. It is often in this adaptation that certain water quality parameters applicable to Koi ponds are overlooked and so some systems could be remarkable successful but do not work properly.

Koi Health begins with successful water-keeping and ends with successful water-keeping. Aquatic life has existed for hundreds of millions of years on this planet. Under aquatic conditions that can be considered "normal and healthy,” Koi should live a long, healthy life, free from disease.

We should therefore, strive to replicate nature in our ponds in terms of a healthy water environment. A healthy pond environment is critical to the long term survival of Koi and it is not that difficult for the average Koi keeper to achieve.

Becoming a successful water keeper and then becoming a successful Koi keeper is far easier for the average hobbyist if they have a clear understanding of Koi pond filtration.

In this series the terms ‘filter’ and ‘biofilter’ will be used to describe the devices that remove solid particles and dissolved impurities (ammonia), respectively, from pond water.

A wide variety of filters and biofilters are available to the koi hobbyist. Many of these have been adapted and modified from existing commercially available aquaculture and water processing equipment. Koi hobbyists must look past advertising claims, past personal points of view and past system complexity to get a broad understanding of pond filtration.

It is a fact that all filters and biofilters work. It is when the human element transgresses certain natural laws of limitation, that failure of the system results.

Bioconversion is a simple and natural process in nature. Nature “works” – it’s as simple as that. The number of living organisms (Koi stocking densities) that can be successfully accommodated in a limited volume of water (the pond) is determined by the amount of dissolved oxygen and the ability of the filtration system to remove toxic wastes from the water. There are limits.

Our ponds are a closed system and have a limited volume of water. In order to successfully maintain a healthy environment for our Koi, we have to clean and re-cycle the same water.

The filter system has to remove the toxic waste (ammonia) from the water as fast as it is produced. The filter must also remove solids and organics (e.g., algae) as fast as they are produced in the pond. We simply have to add oxygen at a faster rate than it is removed. The purified water must return to the pond as fast as possible.

This series on koi pond filtration does not promote a specific biofilter or filter design idea above any other. All filter concepts are discussed as there are many solutions to the problems Koi keepers face.

This series is viewed as a dynamic. New facts and ideas are continually emerging and we turn to the scientific community for information.

A perfect pond can be described as one in which the fish are alive and healthy for some time, the pond is truly clear and the pond does not leak. The rest is robust debate at the edge of the pond on how to achieve this.


Chris Neaves - 2013