of the more popular breeds of fish for the backyard pond is koi.
They are a member of the carp family and are related to the European common
carp (Cyprinus carpio). Interest in koi may range from just
having a few colorful fish swimming around your pond to the more
serious enthusiast who breeds and shows the fish in competitions.
have been bred in Japan since around 300 A.D. and have become very
popular throughout the world. They have been divided into many
different categories based on their color pattern and size. Each
group has a distinct Japanese name which is used by growers to
identify individuals for showing.
special "show koi" may cost hundreds and even thousands
of dollars, plenty of these fish are also available at reasonable
prices for the backyard pond. Perhaps the key consideration that
separates koi from most of the other pond fish is their size. Over
time, they may reach a length of 2 to 3 feet and become
substantial presences. This means that you need a suitably sized
pond to hold them.
A pond of at least 6 feet
in diameter is generally considered a minimum for koi. This allows
enough room for even the larger ones to maneuver easily. While a
depth of 18 inches may be adequate for goldfish, koi should have
at least 2 feet of water. Three feet or more is better in most
cases to minimize rapid temperature changes in the pond.
If you just want a few fish in the pond, you can
treat the koi the same as any other fish. However, if your goal is
to grow championship caliber koi, you may need to have a more
elaborate filtration system and pay much more attention to their
nutritional needs. Special feed formulations are available which
are supposed to encourage brighter coloration and rapid increase
in size for these fish.