Ian Wellby

The guidelines for initial stocking of a Koi pond are 2in of fish per 1ft² (5cm per 0.1m²) of surface area. This will allow the fish room to grow. For example, if your pond was 6ft by 4ft then you would have a surface area of 24ft². You could therefore stock 48in of fish in this pond. The most important factor to consider for a pond is depth. To be able to keep Koi your pond must be a minimum of 4ft deep across some of the depth; this is to maintain an area of warmer water (4˚C) during the winter and to ensure the pond does not freeze completely. The minimum volume a Koi pond should be is about 330 gallons (1,500l). It is also important that the pond has some sort of filter system, unless it is really large and natural. There are a few other golden rules for stocking a Koi pond that you should always follow:

• Add stock slowly so the filter can get used to the new level of stocking and the increase in waste production.
• Fish grow, and Koi can grow very quickly indeed.
• Check the water quality frequently for the first few weeks after adding new fish.