Koi Carp Colour Enhancing Food

Andrew HodgesColour enhancingLeave a Comment


The origins of koi keeping extend back to mans fascination with the marvellous colour variants which developed naturally and were subsequently bred to produce the most exotic, colourful fish we know today.

It stands to reason that an integral part of any feeding regime should include colour enhancing supplements, we want to maximise the colour of our fish, to enjoy their beauty in the fullest.

Where do Nishikigoi get their colour

The key ingredients identified as being responsible for enhancing colour are carotenoids. This is especially true for the red colours.

Carotenoids are a large group of colour enhancing compounds that are stored and exhibited in koi skin. They are a group of chemicals that impart colour by the way they absorb and reflect light.


Commercially produced koi food contains various animal and vegetable carotenoid sources; for example:

  • Krill

  • Spirulina

  • Beta-carotene

  • Astaxanthin

  • Canthaxanthin

“In the wild koi will eat crayfish from a very young age, crayfish are high in carotenoids.”KoiCarpFoods.com

Koi Food additives

The most common food additive to enhance the colours of koi carp is spirulina.

Spirulina is a blue/green micro algae, billions of years ago the oxygen produced by this micro organism would have been partly responsible for the development of life on earth.

It is one of the oldest, most nutrient rich super foods known to man.
The make up of spirulina is between 55 and 70% protein it contains 8 essential and 10 non-essential amino acids and many vitamins.

It is used as a health supplement by humans and is said to give the following benefits:

  • it provides a near-instantaneous energy boost;
  • improves endurance;
  • reduces fatigue;
  • it helps improve the immune system;
  • provides exceptional support for the heart, liver, and kidneys;
  • detoxifies and oxygenates the blood;
  • helps to cleanse the body of toxins and other impurities that may be causing illnesses or other health complications;
  • it is a natural appetite suppressant;
  • it helps to balance the body’s pH, reducing inflammation throughout the body.

Never mind feeding it to your koi carp, maybe you should be adding it to your own diet! You can find out more about the health benefits for humans here.

Spirulina grows in fresh warm water lakes in spirals (as its name would suggest). Its has a deep blue/green colour which gives the water it is in a greenish hue. It is cultivated and harvested in man-made reservoirs.

So what benefits does this marvellous organism have for the fish in your pond?

Koi feeding factors to consider

Whilst maintaining and enhancing the colour of your fish there are several key factors which should be considered:

  • When to feed colour enhancing food

    Only feed colour enhancing food during the primary growing period, when the temperature above 70 ⁰F, generally from late June to the end of August.

  • How long to feed for colour

    As you can over do colour enhancing food, have a specific feeding regime to optimise colour.

  • Use balanced food to be safe

    Provide your fish with balanced, high quality, colour enhancing foods.

In order to build a depth of colour, koi should build layer after layer of of colour, leading to a lustrous quality.KoiCarpFoods.com

Hikari Excel

Many exclaim that Hikari Excel is “The World’s Best Color Enhancing Diet For Koi”

The manufacturer writes the following about this food:

Hikari Excel is a scientifically developed, colour enhancing diet.
An easily digestible food produced from a mixture of highly nutritious wheat-germ and pure cultured spirulina.

After a month of daily feeding it can produce ideal coloration of your koi.

Koi Carp Foods - Koi- Hikari Excel

Japan Mix, for enhanced colour

This food is not specifically colour enhancing food but is consider to contain the vital colour enhancing nutrients. The manufacturers write:

A complete feed with a mix of professional koi food that promotes growth, resistance, and colour of your fish. Available in both 3mm and 6mm pellets.

A complete mixed feed for koi consisting of various types of professional koi food, promoting growth, strength and colour of your koi.

Through the selection of high quality raw materials that are used in these diets, water pollution and discolouration of the pond water is minimal. In addition, the feed is enriched with prebiotic and probiotics which contribute to improve the intestinal health of your koi. A small percentage of this feed sinks (4%).

Feeding advice : At a water temperature above 13 degrees you can feed multiple times a day in small portions. Never feed more than the fish will eat within five minutes.

Analysis average :

  • Crude protein 38%
  • Crude fat: 7%
  • Crude fiber 2.3% – 8.4%
  • Crude ash – moisture 7%
  • 25% carbohydrates (including sugars approximately 2.5 grams)
  • 1.1% phosphorus
  • 1.4% calcium, 0.3% sodium.

Saki hikari colour enhancing koi food diet

This is one of the premium nishikigoi foods on the market and is reflected in its price. It is used by major Japanese breeders and owners who want the best for their koi.

The company states that its flagship product is due to the combination of many years of experience and research, high quality ingredients, impressive technology and strict control on the production process.

Saki Hikari colour enhancing food has revolutionary pro-biotic ingredients and has strong colour enhancing effect.

It has exacting amounts of spirulina to promote vivid colouration and naturally high levels of Zeaxanthin, which is said to improves the Hiban (red areas) of the Koi.

The manufacturer states that this food is most effective when used as a daily diet, stating that intermittent use will not allow the beneficial bacteria to flourish and remain active in the intestinal tract.

Maximum results are achieved when your water temperatures are above 18C (64F).

Saki Hikari Colour Enhancing Typical Analysis:

  • Protein 43.7%,
  • Oil 8.3%,
  • Fibre 0.7%,
  • Ash 12%

Negative side-effects of colour enhancing koi food?

Overfeeding colour enhancing foods can adversely affect the white background of your nishikigoi.

Whites can turn a brown/yellowish or greenish colour which is most undesirable. This discolouration is usually only temporary and should clear up in time. Be aware that the time is months not days or weeks, so if you overfeed prior to a show, there is no quick fix.


Natural or artificial colour enhancers

There are two approaches to enhancing colouration in koi the precise approach using synthetic colour enhancers and the less efficient approach using natural sources of carotenoids.

Natural sources:

As with any natural commodity, qualities and pigment content varies from source to source. Being organic there can be degradation during processing.

Natural sources, however, are renowned for offering superb range of carotenoids giving koi excellent colour potential. Marigold petals have more than 20 different carotenoids, which koi can assimilate and manipulate for colour.

Marigold petals have a high concentration of carotenoid compounds (approximately 9000mg per kilo), whereas shrimp or krill meal will only have about 200mg per kilo, with the added issue of the exoskeletal material having a high ash content.

There is a price to pay for koi using natural carotenoid sources, the process of converting them into more desirable astaxanthin requires energy.

Artificial sources

Research has led to the formulation of potent, stable and effective man-made colour enhancers.

Rather than feeding a natural source of carotenoid in unknown quantity or quality, a controlled dose of pigment in the final form in which it will be used is offered.

Providing nishikigoi with a precise amount of pigment in a form which will most easily be deposited in the skin is the basis of this method.

Premium koi diets will contain ‘safe’ levels of colour enhancers, giving the benefits of a precise and effective formulation. Look for foods with the following ingredients as they will enhance the colouration of your koi.

Top colour enhancing compounds:

  • Spirulina

    This has an above average carotenoid content that is easily assimilated

  • Paprika

    Red Pepper Meal. More potent than spirulina, and contains red pigments ready to be absorbed and assimilated

  • Marigold

    Flower Meal. Probably one of the most potent natural sources of carotenoids available. The pigments require manipulation by koi to convert them to reds.

  • Artificial Colour Enhancers

    Astaxanthin and Canthaxanthin are guaranteed, potent sources of colour in the form that will be exhibited immediately in the skin.

  • Yeast

    Phaffia rhodozyma. This is easily digested and is a recognised source of carotene and astaxanthin.


Leave a Reply

Your email address will not be published. Required fields are marked *