When choosing the quality of Koi there are 10 things to look out for: variety, balanced colour, colour strength, shape, fins, eyes, diet, supply, cull, tategoi and combination.

Variety - I recommend you get to know the most popular varieties of Koi and what to look for in a high quality fish from each variety. The difference between viewing a pond of high quality fish is amazing compared to viewing a pond of low quality fish. The quality fish stand out like amazing gems compared to the lower quality individuals. There are so many different varieties of Koi but the most popular are Kohaku, Sanke, Showa, Bekko, Utsuri, Ogon, Matsuba, Asagi, Doitsu, Tancho and Kinginrin.

Kohaku – is a white fish with red markings.
Sanke – is a white fish with red markings the same as a Kohaku but also extra black markings on top of the fish, but not on the head.
Showa – is a black fish with the same markings as a Kohaku that has also got a white pattern. So a white fish with red and black markings is a Sanke and a black fish with red and white markings is a Showa, only Showa will have black on the head. A Showa has black at the base of the pectoral fins (moto guro). Sanke can get small streaks of black on the pectoral fins.
Bekko – is a white fish with black markings on the top of the fish. It is the same as a Sanke without the red.
Utsuri – is a black fish with white markings. It is the same as a Showa, without the red.
Ogon – is a single coloured metallic Koi.
Matsuba – has black in the centre of each scale. This is called the pine cone look.
Asagi – has a Matsuba pattern on the top of the fish with red along the bottom, sides and in the fins. A Doitsu variety of the Asagi is called a Shusui.
Tancho – is a variety of Koi with a red spot on its head. This is very significant to the Japanese because of the similarity to their national bird the Tancho Crane and their flag.
Kinginrin- are Koi with metallic sparkling scales.

Japanese terms often used in Koi talk:
Tategoi – is a young Koi (unfinished)
Manware – is black pattern on the head
Sumi – means black in Japanese
Hi – means red spots in Japanese
Hikari – means it looks shiny
Inazuma – means it has a zig-zag lightning pattern across the top of it
Aka - means the fish is mainly red
Ki - means yellow in Japanese
Moto guro – is black at the base of the fins
Doitsu – means the fish is mainly covered in skin not scales
Ginrin – is a Koi with metallic scales
Rin – is a scale
Gin - is silver
Kin – is gold
Orenji – is orange 

Balanced colour – When looking at a Koi from the top it is important that the colour is balanced from front to back and left to right. If the pattern is stronger on one part of the fish then the fish will look unbalanced in the pond and the key to a perfect Koi is for it to look perfectly balanced in the pond.

Colour strength - The strength of the colour will determine the quality and value of the fish. It must also be remembered that the colour of a Koi is constantly changing e.g. many fish that are amazing as a baby will fade as adults, while others that look too dark as babies will develop into amazing show Koi as adults.

Shape – The shape of a Koi is very important. They should be a solid but balanced torpedo-shaped fish. The more imposing the fish looks in the pond the better the fish is, as long as it doesn’t look overweight. The female will naturally look a lot chunkier than the male and often more impressive.

Fins and scales – The fins on a quality fish should be large, clean and balanced. The fins should be expanded and allow the fish to glide effortlessly through the water. They should not be frayed, split or appear brittle, powdery or have streaks of blood which indicates stress.

The scales of a Koi should be clean clear and well aligned; each scale should match up beautifully to compliment the pattern of the fish.

Eyes – The eyes must look sharp, clean, clear and alert. They must not look blood shot, glazed over or covered by a white film. 

Diet – As with all fish it is important to feed these fish a balanced diet of high quality foods. Higher quality foods produce a stronger immune system, better colour and will help to keep a cleaner pond. In summer the fish may need to be fed every day while in winter up to twice a week. It is easy to monitor how much food the fish should be fed by the shape of the fish’s belly. When viewing the fish from the top the width of the belly should be slightly wider than the width of the eyes in female and about the width of the eyes in males. If the belly is too thin then slowly increase the food, if the belly is too fat then slowly decrease the food. If you want your Koi to grow very quickly then they can be fed twice a day in summer as long as you are prepared to do adequate water changes to allow optimum water quality to be maintained.

Supply – The colours of a Koi are random and every fish is unique, but the odds of getting a high quality fish are still far higher if you get the fish from quality stock. Try to buy your Koi from a knowledgeable supplier that knows what they are looking for and carries healthy, strong and well-maintained stock.

Cull – The best way you ensure you get a quality fish is to buy many more than you need and each year sell off the fish with the least promise. For example let’s say you start off with 100 hand picked high quality babies and sell off 10 each year, you will end up with about 10 wonderful jumbo fish after 8-9 years. Culling the fish can be a way for someone with patience to enjoy watching as their fish develop over a period of time, allowing them to have high quality fish without the expense.

Tategoi – The Japanese term Tategoi is used for unfinished fish. Unfinished Koi display Kiwa (see below) and are fish that will get better coloured as they grow. When you are looking to buy a Koi you must realize how big they are likely to get in your pond and how many you need to have in order for them to reach and keep their full potential. 

How sharp the edge is between the colours is the Kiwa. The sharper the colour, the better the Kiwa is said to be. For example if the fish is white and has strong red with a light red perimeter to the trailing or leading edge then the Kiwa is weaker. As the fish grows it will fill out the light red as the colour is under the surface of the fish and will come to the top as it grows. Once the fish has perfect Kiwa it is said to be finished. As the colour is already at the surface of a finished fish it is likely to break up and fade as the fish grows. 

If the fish has balanced Kiwa then it will mature with even colour. If the Kiwa is unbalanced then the colour on one part will display great definition while the fish will display low definition on another part of the fish. This will mean the fish will never look as striking as a fish with balanced Kiwa, it may appear more muddy looking.
The size that your fish matures or finishes in is important to understand as the larger the pond, the larger the filters and the more water changes that are done, the bigger the fish can get.  The more fish you get, the smaller the fish will stay as each fish releases chemicals such as pheromones that will stunt the growth of all the fish in the pond. 

A finished Koi is a fish that is as good as it will ever get. Each fish will be finished at a different time, some fish finish young while others can be jumbo and still unfinished. Finished Koi can be very expensive and anyone looking to buy these fish must be prepared to pay top dollar knowing that as the fish grows they are likely to deteriorate in quality if this fish is kept in a pond that will allow it to grow further. These fish are often selected for display ponds that are not too large and where each fish must make the biggest impact possible. These smaller ponds cannot rely on culling as the fish will never grow at a speed that will give the owner the effect they are looking for.

Combination – The combination of fish that you choose for your pond will govern the overall look and affect how striking the pond is. It can look best if you pick a certain variety to be dominant in the pond. Sometimes a pond with one of each type will lack strength in the colour and allow all the colours to seem to blur together. The most popular varieties by far are the Gosanke Koi which are Kohaku, Sanke and Showa. It is common for a pond to be made up of 50% Gosanke while only one or two of the others like Bekko, Utsuri, Ogon, Matsuba, Asagi, Doitsu, Tancho and Kinginrin. Ponds with a majority of other varieties such as Ogon look unique but often lack the class of a Gosanke pond. 

It is important that you cull out most of your dark fish as they lack the imposing nature of the Gosanke. Any pond should not have more then one or two of the dark type such as Chargoi or Magoi, because they tend to get large and take up a lot of space for very little impact.

Remember that unless you are showing your fish the only thing that really matters is that you are able to maintain healthy fish that you love. High quality fish typically look far more striking but which individual or variety is best is still up to your personal opinion.

Good luck and enjoy
Paul Talbot