Goldfish Koi Keeping For Beginners

A water feature can provide an additional dimension to the life of a garden. The sound of moving water dappling down a waterfall to the pond surface offers a worthy accompaniment to fluttering of vibrant flowers and shady foliage moving in the breeze.

Gardening horizons can be broadened by stocking that same pool or pond with fish, offering vivid colour down to the depths of the pond.

Many would-be aquatic gardeners may be wary of adding ornamental aquatic life to their pond, but as long as a few basic ‘rules’ are followed, fishkeeping can quite easily become another facet of the water gardeners skills.

The nature of the beast

Fish keeping is unlike keeping any other ‘typical’ pet, such as a cat, dog, rabbit, or hamster etc, in that they live by a completely different code.

The sooner the nature of a fish’s requirements are understood, the sooner fishkeeping can be mastered.

Fish are cold blooded, and as a result, their behaviour patterns are largely determined by the temperature of the water. They are active in a garden pond from March through to September, feeding and growing most actively in the summer months. These are the months when most interaction occurs between the pond owner and the pond’s inhabitants, with young fish often doubling in size and often becoming so tame, that they will feed from you hand.

Water quality

Fish pollute their environment just by living in it. They are constantly excreting toxic wastes (ammonia), which can accumulate in the water, making the water toxic also. If this is allowed to take place unhindered, then fish will become stressed and diseased. The solution to this is to install a pump and biological filter which if allowed to mature, will keep pace with the waste, breaking it down before it pollutes the water. A bio-filter is an essential living part of every pond’s environment, full of friendly bacteria that carry out this essential function.

Ponds should be stocked gradually over a number of weeks to allow the bacteria in the filter to develop and mature, keeping pace with the waste that the few fish produce. As time passes, more fish can be added slowly so that the filter can mature steadily until the limit of the pond has been reached. Partial water changes of 30% should be carried out every fortnight in the warmer months to dilute residual contaminants and to freshen up the pond life generally.

The success of keeping fish in a pond relies on providing them with as stable and unchanging environment as possible. This is best achieved by installing as large a pond as possible, using a bio-filter, and feeding them a premium balanced diet. If all goes to plan, they will reward you by growing and breeding, making many new additions to the pond.

The choice is yours

The variety of pond fish available in garden and aquatic centres is quite astounding. All but a few oddities (such as sterlets) are members of the carp family, and are selected for their colour, finnage, size and shape. Those fish available include goldfish (of which there are over 300 varieties!), including the more common comets and shubunkins. Golden orfe will dart about in the surface of the pond, where as golden tench will act as scavengers on the bottom. For larger, deeper ponds, koi and ghost koi are excellent prospects for growing into much larger and magnificent specimens.


Feeding pond fish is only really a 6 or 7 month occupation, and even then it is not a full time responsibility. Fish are best fed 2-3 times a day using a quality pellet, stick or flake food (or a combination of all 3). The choice of food reflects the variety of fish and sizes available, with flakes suiting the smaller fish and fry, moving on up to larger sticks and pellets for larger fish, particularly koi. Furthermore, fish have a highly efficient metabolism compared with other ‘pets’ and as a result, can easily manage without food for a 2 week vacation. After all, it’s not as though they are likely to dehydrate!


Besides the warmer summer months being the peak period of activity, feeding and growth, it is also the time that fish will breed in a garden pond. Breeding can often be mistaken for aggressive behaviour as it will often result in a splashing frenzy where amorous males bombard plump females with their physical attention. Goldfish and their relatives will release several thousand tiny adhesive eggs that will attach to submerged aquatic plants, hatching into fry several days later. They require a dense coverage of aquatic plants in which to take refuge until they are large and fast enough to avoid being eaten by other fish, including their parents.

Kill blanketweed and string algae.