Japanese Koi Fish

The Japanese koi fish pond is certainly nothing new. As far back as 2,500 years, Koi was found in China and Eastern Asia.

The Magoi or black Koi, of China and Eastern Asia, was known for its high nutrient content and even kept in the rice paddies for food in winter.

About 700 years later the Magoi was bred with other red mutants to create some of the gorgeous colors we have today. Koi, known as Nishikigoi in Japan, is the national fish of Japan. These "colorful carp" in shades of white, yellow

and all red, originated in what is now known as Iran.

Koi fish have been bred in Japan since the 1820's, initially for food but some of the fish came up with red and blue mutations. Through a breeding process the fish became what we know as Koi in 1870.

Even Germany had its own version, known as the Leather Carp, introduced around 1830. Today, there are over 100 color varieties, with each Koi being unique. Koi have become very collectable among koi fish pond owners the world over.

Modern Koi

Every country in the world has Japanese koi fish breeders now and these fish are the most popular for decorating the pond. Their colorful bodies make them most desirable with the largest Koi going for several hundred dollars each. There are other features that play into how important a particular Japanese koi fish becomes such as shape, volume, if there are any deformities and the list goes on from here.

Color depth and luster are qualities looked for in Koi, especially in the metallic varieties. Next is personality as they swim in your pond. As we mentioned in another page, you can train your Koi to eat from your hand, but you can also install a floating feeding ring, adding to your enjoyment of these smart creatures. Soon after installing a ring, the Koi will gather at the ring much like people do at a water cooler.

Keeping koi fish

Most likely the first thing you will think about if you are going to be keeping Japanese koi fish is in what will you raise them. There is no better place than a backyard pond.

The size of your pond will determine how many fish you place but even a small Koi can grow some 2-4 inches a year. Don't forget that good aeration and feeding methodology will also determine how large your Koi grow.

With the average being around 24-36 inches, a very small pond will have a very few Koi and keep them healthy. To keep Japanese koi fish disease free you must keep them stress free and your pond in top working order. See our pond maintenance page. Causes of stress can range from high ammonia level, low oxygen levels, poor water quality, crowding, water temperatures, too much handling and moving of fish, toxic chemicals(lawn and garden,etc) to name a few.

The best defense is to prevent these stressers because it is far easier to be careful than it is to treat your pond.

Filtering Koi fish ponds

Filtration of your Japanese koi fish pond is absolutely one of the top priorities in providing a healthy environment for your fish and to keep the water clear so that you can see your Koi.

Just having crystal clear water does not guarantee quality water, though. If the pond is algae free then it could also be so toxic that fish will not survive. The way to ensure a healthy pond is through biological and mechanical filtration.

A bio filter actually reprocesses fish waste into clean water through the micro organisms that grow in the filter. For this reason a pool filter is not adequate because a pool relies on chemicals to help the filter do its job. Very little ammonia, or fish waste and solids are found in a swimming pool. In addition, the pump for a sand filter would need to run 24-7 to do the job, running up your electric bill as well.

Biological filters come in basically three forms, in the pond down flow filters, or out of the pond down flow filters, and out of the pond up flow filters. The out of the pond types are easier to use and maintain. Also be sure to include a UV sterilizer.

How to choose the right bio filter is a matter of purchasing the best possible filter that you can afford. For small to medium ponds you can go with a combo filter. Biofilters should be pressurized in order to get the pond water to flow over the top of a waterfall and they should also be self cleaning to reduce routine maintenance. Pressurized pond filters work well for the majority of koi fish ponds and garden ponds.

Feeding Koi fish

Since Japanese koi are bottom feeders but can be trained to take food from your hand, most Japanese koi fish food is made up of both sinking and floating matter.

One advantage in using floating food is that you can readily see when the Koi have had enough to eat and thus remove the food before it breaks down and sinks to the bottom of the pond. Once food sinks, it will decompose and will be harder to clean out of your pond.

A good rule of thumb is to give enough food for five minutes of eating time, taking care to provide smaller pieces for the young Koi. You can offer a mixture of both small and larger pieces if you have fish of various sizes, but do take care to make sure that the young are fed adequately otherwise you may lose them.

If you wish to have color enhanced Koi, particularly good for koi fish pictures, certain additives can be added to your fish's diet, but remember that the best color comes from healthy fish.

Keeping your pond healthy will help keep your fish healthy.
Japanese koi fish also love live foods such as worms, high in protien and great when you are trying to train them to eat from your hand. Just remember that such live foods are only treats and meant only to supplement the vitamin, mineral, and amino fatty acid rich food meant specifically for Koi.

Once in a while you can offer brown bread, never white. Koi also will eat lettuce leaves and duckweed and other plants around your pond, so if you treasure a given plant, do keep it away from your Japanese koi fish.

Koi and the seasons

For reasons that are obvious to most people living in the Northern half of any country, heaters are added to their ponds. Optimum temperature ranges for Koi are between 55 and 82 degrees farenheit. Above or below these ranges trigger the survival instinct in the Koi and depending on their age and condition, it is possible to lose Koi in very cold or very warm conditions.

Most Koi are very resilient and will survive and manage in the lower or upper ranges but you must understand the metabolic needs of your fish in order to help them survive. Koi naturally slow down for a period of about 6-8 weeks in winter and especially if the temperature in your pond dips to 45 to 55 degrees. This is the time to withhold feeding for the Koi will not be interested. To learn more about winterizing your koi fish ponds, see our page on winterizing your pond.

For people living in the warmer climes, the need to keep the pond cool is just as important. Specially designed de -gassing units will remove toxins as well as help to keep koi fish ponds cooler.

In preparing for spring, the signs that a transition is about to happen will be subtle at first. As air temperatures rise the water temperatures will slowly rise bringing your Koi out of its winter slumber. Water quality tests need to be done as soon as you notice this activity. Use an accurate thermometer to gauge water temmperature for this is the only way to see when your Koi are up to speed and will begin functioning. Once they do, they will need to eat, thus starting the cycle of pond maintenance once again.

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