alimentacion koi

Feeding koi – crucial for the development of your koi

Feeding koi – an essential chapter if you want to have good koi. 

As for people, feeding the koi has two main functions:

  • source of power
  • source of growth

As for individuals, the quality of food is essential. But while human are not concerned too much about our excrement, we are very interested in the one of our koi, because it might mean more work or even filtration problems, poor water quality and consequently sick koi. 


alimentacion koi

Feeding koi – a very well developed koi


A diet of poor quality (e.g. those sold in garden centres that look like colorful worms, but if you crush them, then you have nothing than a light powder) is manifested not only in the discomfort of koi, but also prevent good growth and have immediate consequences for the filtration system (which in turn characterizes the quality of water, the habitat of the koi).


In nature we see that the koi are omnivores, meaning their diet consists of both plant parts (approx. 70%) and animals parts (approx. 30%). In their natural habitat you will notice that they are constantly with the nose in the mud – translated: they eat all day. That is because the fish have no stomach and all the work is done in the intestines. Therefore it is more convenient to give the koi to eat several times (5-7) per day, instead of once lots of it.


The easiest way to find the right amount is a very simple rule: the quantity they can eat within 5 minutes. If after 5 minutes there is still food floating, you know that the next time you should give them less.


But we would also like to provide you the scientific formula to calculate the optimum amount of feed:
1% of body weight for nutrition of the koi
2% of body weight when the koi are still growing


For instance:

5 x 1,4 (obtenido de 2% de 70 gramos por koi) = 7g
4 x 5 (obtenido de 2% de 250 gramos por koi) = 20g
2 x 20 (tenido de 2% de 1000 gramos por koi) = 40g

67g por día (repartido en 5 veces en verano), así que un cubo de 4 kg de pienso debería bastar para unos 2 meses.

5 Tosai (1 year) approx. 15 cm approximately 70 grams each
4 nisai (2 years) of approx. 25 cm approximately 250 grams each
2 sansai (3 years) of approx. 40 cm about 1000 grams each 


5 × 1.4 (calculating 2% of 70 grams per koi) = 7g
4 x 5 (calculating 2% of 250 grams per koi)= 20g
2 x 20 (calculating 2% of 1000 grams per koi)= 40g


This makes 67g a day for which a bucket of 4 kg feed should be enough for about 2 months.


alimentacion koi

Feeding koi: a special relationship between koi and human


Los koi son peces de de agua fría y su metabolismo (y por lo tanto también su digestión) se regulariza según la temperatura del agua. Es decir: en verano, los koi son más activos y necesitarán más alimento y un alimento más potente.


For people who can not feed several times a day, there are automatic feeder that can be scheduled various times of the day and it has many other advantages, too.


If a koi does not eat regularly, it is a signal and should be observed for a while. It may simply have “a bad day”. But it can also be an indication of disease.


Koi are cold water fish and their metabolism (and therefore also their digestion) is regularized by the water temperature. This means, in summer, koi are more active and need more food and a more powerful food.


In winter, koi are less active and require less food and in a different composition (less fat). When the water temperature is less than 8 degrees, you should stop feeding them. In areas where the water temperature is always above 8, you should choose the coldest period to stop feeding them for at least 2-3 weeks (depending on the size of the koi) and thus enable them to live their natural bio rhythm. This time of fasting will help them to lose body fat and possible excess of eggs. 


alimentacion koi

Feeding koi: different sizes of pellets


 Food ingredients and their contributions:


  • Proteins: cell regeneration, muscle development (there are proteins of animal and vegetable origin)
  • Carbohydrates: energy source (the cheapest of the food ingredients, usually soybean meal)
  • Fats: energy source, important for creating hormones
  • Fibers: aid digestion and stimulate the intestinal tract
  • Vitamins: growth resistance (water soluble B, C; soluble A, D, K, E)
  • Minerals (specially iodine) and spores (specially algae): oxygen transport, growth
  • Ashes: no nutritional value
  • Pigments: carotene, astaxanthin


Attention ! Pigments often contain a lot of spirulina that is usually given to improve the color of koi. Using it too often can stain your koi pink !!! Best give it only in summer in combination with summer food.


Feeding koi is a very important chapter and should be studied carefully. If you have any questions, please feel free to contact us.


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