Japanese Koi Fish

Into this dynamic pond system we introduce two critical factors - fish and man. How can our Koi possibly survive in an environment that can become 100 - 200 times more alkaline / acidic, have a temperature change of more than 5C, have oxygen levels that can drop and rise dramatically, and have a shifting ammonia / ammonium percentage in a single day? How can our fish possibly survive the bombardment of toxic chemicals which are added to the pond in the name of medications?

The average enthusiast does not have the hundreds of thousands of rands to spend on equipment to monitor the water continuously. How can he possibly monitor all these IF's (Influencing Factors) continuously, make daily adjustments and provide the perfect environment for his Koi?

The answer is simple - if your Koi are alive and healthy and growing well - you are doing it right. Your Koi are the best test kits you have. It may be a joke amongst Koi collectors that when a new pond is built they always suggest placing a few "pH testers" into the new pond to "test" the water. A joke yes - but it is an excellent way of testing the water for your new arrivals and new pond system.

Koi (coloured carp) have been living successfully in freshwater rivers for millions of years. There are fossilised remains of the direct descendants of carp. It is a scientific fact that whilst a pH of 7 - 7.5 is advocated as "ideal" for keeping Koi. Koi will live comfortably in a pH range of 6.5 - 8.5.

A temperature range of 22C - 28C is ideal for keeping Koi. However, they winter well down to 10C. And provided the temperature is not below 8C for too long a period of time, they suffer no adverse affects after winter. The critical factor is these fluctuations must be gradual. Actually the less the fluctuations or the more gradual the fluctuations the less stressful the environment.

Oxygen levels are maintained by circulating the water correctly in the pond and by bringing the water into contact with the atmosphere continuously. The faster the turn-over rate of the whole system, the better.

Ammonia levels can be controlled successfully by providing additional surface area for bacterial growth. This extra surface area is often referred to as the bio-filter or bioconverter. The high oxygen levels provided by high turn-over rates will activate the bacteria and the metabolism of the fish.

The natural immune systems and osmo-regulation of the fishes body is adapted over millions of years to counteract natural fluctuations in the water and attacks from the outside world. Provided the fluctuations are not too great or too sudden the fish has the ability to adjust and survive the daily, monthly and annual bio-rhythms of the pond.

Chris Neaves