The Best Growth Enhancing Food For Koi Carp

Andrew HodgesGrowth, Water QualityLeave a Comment


After water quality, selecting Koi food is probably the next most important aspect of responsible Koi keeping. Maintaining perfect high-quality water is dependent on the quality and quantity of food we add to the pond.

Which Koi Carp food should I chose for maximum growth?

This question is most often asked by new koi keepers searching for the panacea. How do I grow my small, affordable Koi Carp into Jumbo Koi like the ones at my Koi dealers which cost an absolute fortune?

In truth food alone will not get you there. At the beginning of my koi journey, I tried this approach and was disappointed with the results. Because I did not understand the whole picture, the fish were not in high-quality warm water.

Lots of High-Quality food with high protein content is required. But an often overlooked aspect is that a filter system with relatively massive capacity is needed.

Perfect water will produce perfect Koi Carp.

A large filter is necessary to remove both the mechanical or visible solid waste and biological waste. Biological waste comprises the dissolved toxins such as ammonia produced by the fish.

Fish do not pollute the pond water. The fish in your pond are cleaning and filtering out the primary pollutant in your pond. The main pollutant affecting our pond water is the food which we regularly throw into it.

Koi carp in clear water
8570442 – koi carps swimming in a water garden

Pond keepers think that fish are polluting the water. If you put food into an empty pond, it would naturally break down into ammonia.

Fish convert food into heat, new cells for repair and growth. With fish in the water and the same amount of food put into the pond, the quantity of Ammonia is less.

Uneaten food is polluting your pond; this is why it is so important not to overfeed your Koi. You should remove any uneaten food as soon as practicable.

“Do not overfeed your pond and filter!”

Koi up to one year old can consume between 5 and 10% of their body weight in food each day. From one year to three years the amount of food is reduced to around 5% of body weight.

For fish, over three years of age, the amount of food is reduced further to 2% of their body weight. Several small meals throughout the day are preferable to one large feed.

But it is essential that your pond filtration system is capable of dealing with such massive feeding rates.

Water temperature affects growth more than food.

A koi carps ability to process and use protein to grow is temperature dependent. Japanese koi breeders report that they do not see significant growth at temperatures below 65 degrees Fahrenheit.

At around 59 degrees Fahrenheit koi are only able to utilise approximately 87% of the protein provided in their food.

When the water is warmer, 68 to 77 degrees Fahrenheit they can utilise 89% of available protein.

Also of note is that the digestibility of protein reduces dramatically in water with low levels of dissolved oxygen.

Below 50 degrees Fahrenheit koi will usually stop feeding altogether. If they do want to eat, we can feed wheatgerm feed at a lower temperature.


Are all growth foods made equal?

In general terms, we do get what we pay for where koi food is concerned. I do think, however, there is one caveat. Food imported from Japan is much more expensive.

This extra cost, due to transportation, does not necessarily mean that it contains any mystical components. High-quality Koi food manufactured in your own country will probably have very similar ingredients.

There is a fascination with Japanese Koi breeders and sourcing the specific food that they use is fair enough. If that is what you want to buy that is great.

My point is that you do not have to spend a fortune on Koi food to get a high-grade product.

Low-quality food may be less digestible and lead to poor health, more waste and a polluted pond.

beautiful Japanese pond

What are the main ingredients of good Koi Carp food?

To promote growth, enhance vivid colour and develop a robust immune system Koi Carp require the following in their diet:

  • Protein
  • Fat
  • Vitamins
  • Minerals – Crude Ash
  • Immune system booster
  • Colour Enhancer
  • Trace elements

Why do we only talk about Protein for growth?

Proteins are molecules made up of hundreds of smaller units known as amino acids.

A koi carps diet must include thirteen essential amino acids. The proteins found naturally contains twenty amino acids. The prime sources of protein for koi food is fishmeal; this has become much more expensive in recent times.

Some koi food manufacturers will look to cheaper plant based or animal proteins.

High-quality proteins are essential for growth, tissue repair and maintenance.

Koi carp cannot store any excess protein in their bodies; therefore it will have to be expelled. This excretion enters the pond water as ammonia and a small quantity as urine.

Essential Fatty Acids

Fat or fatty acids are an energy source; they also help absorb fat soluble vitamins. Certain fats are known as essential fatty acids, necessary for optimum health.

If essential fatty acids are absent from the diet, fish may suffer poor growth, fin erosion, liver and heart disorders.

Carbohydrates – don’t give your koi a pot belly.

Carbohydrates provide energy; they can also be used to produce non-essential fatty acids. Too much glucose can be dangerous for koi as they will store the additional sugars as fat. If fish overeat, they may develop a dropped belly.

By providing the fish exercise, in the form of strong water currents, any extra calories can be used up trying to keep still.

Fish also need multi-Vitamins.

To stay fit and healthy koi carp require many vitamins. Fish cannot synthesise vitamins, in sufficient quantities, from the other food ingredients.

Many vitamins are unstable and may deteriorate during food processing. Food manufacturers add vitamin supplements to ensure that the finished food contains sufficient vitamin levels.

Orange halves

The many and varied Minerals

Crude Ash is used in food to provide a wide variety of minerals. Minerals include calcium and phosphorous which are vital for healthy bones. Sodium and potassium are essential for healthy nerve function, and magnesium is crucial for healthy metabolism.

Trace elements

In the trace elements, i.e. in tiny quantities, are copper, iron, manganese zinc and iodine.

Colour enhancer

Specific food with colour enhancing properties can only be used in the warmer months of the year. Shrimp meal and Spirulina Platensis algae extract are both colour enhancing additives.

What are the best Koi Carp foods for Growth?

One of the most highly regarded brands of koi food is Saki Hakari, which contains “Hikari Germ” to aid in waste removal. We are not sponsored by or have any affiliation with Hikari.

The “Hikari Germ” reduces waste buildup in your filter media reducing the frequency of maintenance. Koi keepers who switch to this feed commonly note vast improvements in water clarity and condition.

Hikari experimented with two separate ponds. One of the ponds was fed Hikari and the other a standard koi food. After 18 days of feeding 30 fish 2% of their body weight per day, the filters were cleaned out.

The filter media of the pond fed Hikari had half as much accumulated waste as the other test pond.

On their website Saki-Hikari state that their Growth Diet will help your koi carp develop into superior jumbo koi of your dreams.

Years of research at the Hikari Aquatic Lab has led to the development of the perfect koi food recipe. Hikari Growth offers maximum, fat-deposit-free growth with no adverse side effects. Typical ingredients are:

  • Crude Protein: min 40%
  • Crude Fat: min 9%
  • Crude Fiber: 2.0%
  • Moisture: max 10%
  • Ash: max 17%
  • Phosphorus: min 1.7%

Kyorin Food Industries, Ltd undertake production of Hikari Brand foods.

This food is shipped from Japan and is pretty expensive, but if you have spent thousands on your koi carp, the price will probably not put you off.


Many brands the same factory – less expensive food

A wide variet of high to mid-range brands of koi food are produced in the Netherlands by Alltech Coppens.

Companies buy food from the manufacturer and re-package the food under their brand.

My point here is that many varieties of food in the koi dealers is very similar if not the same. That’s not to devalue them in any way. The best way to find a diet which suits your pond is to buy a small bag and try it.

In no particular order and with no affiliation, here are some of the more popular koi carp food manufacturers for you to research.

  • Hikari (Japan)
  • JPD (Japan)
  • Kusuri (UK)
  • Dai Suki (UK)
  • Orchard Fisheries (UK)
  • Queni Koi (UK)
  • NT Labs (UK)
  • Sera (Germany)
  • Boddington Koi Food (UK)
  • Evolution Aqua (UK)
  • JBL (Germany)
  • Kodama (USA)

In summary – it’s not all about the high protein.

So I hope if you have read this far, you can see that there is not a simple answer to the question. There are many excellent koi carp foods designed for growth.

What we need to ensure is that the whole picture is complete before we spend top dollar on the excellent high protein food from Japan.

I hope this article was helpful. Thanks for reading.

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