Top quality hand selected
Japanese Koi Carp at sensible prices

Dormer Cottage, Spurgrove Lane, Little Frieth,

Nr. Henley on Thames, Bucks, RG9 6NU

Phone/Fax: 01494 882600

Order Hotline: 07814 011357

last updated 22nd October 2014

How to feed your Koi

At Koi Water Garden, we are able to offer competitive prices on high quality koi foods, and also explain the hows and whys to ensure you feed your Koi the correct way.


How to feed your Koi, how often, how much and with what?


Koi are, like all members of the Carp family, omnivorous, and will eat a very wide range of food. In their wild habitat, they are like other members of the carp family, bottom feeders and use their twin pairs of barbels in order to help them locate food in the detritus at the bottom of ponds and rivers. Their diet is varied dependent upon the environment in which they live, but much of their food is live food.


In our artificial pond environments their diets are strictly governed by what their owners are prepared to feed, in terms of variety, how much and how often. We can still give Koi a wide range of foods, even though all the vitamin and nutrient content they need is available to them via all good pelleted Koi foods. Unlike their wild cousins, our Koi live in very small volumes of water, which has to be carefully filtered and monitored to ensure prime water quality, and the type, and amount of food we give can have real impacts on water quality and so how we feed our Koi is vitally important to their well being both directly and indirectly.


Koi feeding


What to feed?


Unlike their wild cousins, our Koi are highly inbred in order to produce the colours, patterns and body shapes that we find so desirable. This means however that the immune systems of our Koi are much weaker than with wild Carp and they are in all respects genetically weaker. Their diet then is even more important, and the correct balance of vitamins and minerals and other trace elements is absolutely essential to long term health. You should therefore ensure that only diets specifically designed and developed for ornamental Koi are used at all times as a basic diet.


All 'proper' Koi foods available in pellet form today contain a wide variety of vitamins and minerals as well as proteins and other important additives such as anti-oxidants and trace elements, all of which are needed in our Kois diet in order to ensure they stay healthy and can develop and grow to their full potential. We can however supplement a Kois diet with a wide range of other foods. Favourites are brown bread - with or without honey added, prawns, cockles, worms, sweet corn, oranges, cheese, lettuce and more. However, most of these items should be given sparingly, and as a supplement to the normal diet, not instead of. In particular, bread contains little goodness and should be used sparingly.


Unfortunately, our in bred pets will , like their wild cousins, eat cat and dog food, sausages and other 'junk' foods and like humans, don't always seem to know what is best for them, so these kinds of foods are best avoided. Also avoid at all costs, basic pelleted foods that are used purely for growth, such as trout pellets, since these diets contain little or no vitamins, only proteins for growth, and their long-term use can detrimentally affect the health of our Koi.


It is also important to vary the diet throughout the year, even using different brands of pelleted foods, as Koi can quickly become accustomed to one type of food, and will often turn their noses up at new foods if they have gotten too used to just one boring diet.


All the major branded Koi food we offer are specialised and balanced Koi diets which contain all the necessary vitamins and trace elements that Koi need. Some are specially medicated diets that contain immuno stimulants such as Stimune or Propolis and yeast derivatives which are proven to boost the immune system of animals when administered correctly. Some contain specific additives, to enhance colours, some contain high levels of proteins and some low levels of proteins to cover the requirements for every season. Some of these foods are now Probiotic and contain bacterial cultures that aid or improve digestion and food assimilation.


Some of the dietary supplements mentioned above are definitely acquired tastes, and you may find that when trying to tempt your Koi with, for example, lettuce or oranges for the first time, these new foods are completely ignored at first. Persevere however, and you will soon find that the Koi come to expect and relish these treats.


One can of course also vary the diets of Koi by mixing pelleted food with other supplements to add more vitamins, immuno stimulants, or just to make the food more tempting. Favourite additives are honey, orange juice, propolis and montmorillonite clay. When mixing your own concoction, only mix enough for a few days so that the food stays as fresh as possible.


To make a batch of your own food we would suggest starting with 1/2kg of good quality pelleted food. In a suitable container add 250ml approx of warm water, and to this add 1 heaped teaspoonful of your favourite honey, two tablespoons full of orange juice and a teaspoon of raw propolis. Note when using raw propolis you will need to use warmer water to overcome the resinous nature and get it to dissolve properly. Mix thoroughly and then add to your food in a suitable container with a lid and shake or stir gently to ensure that the liquid is properly dispersed and mixed. leave to stand for 15 minutes to ensure that all the liquid has been absorbed by the food than take 1 heaped tablespoon of montmorillonite clay and spread over the pellets. Return the lid to the container and shake well so that the pellets are evenly coated with the clay, which will take on the appearance of icing sugar. Your recipe is now ready for feeding! Store in the fridge between feeds. Please vary the amounts of the ingredients to suit you Koi stocks.


Even in our artificial concrete ponds, Koi will find some natural food, especially in warmer weather. There will always be a population of Rotifers present in a body of water, and the Algae and weed growth present in most ponds makes the perfect home for all sorts of tiny pond life, most of which our Koi will consume with relish. Infusoria and Daphne are very common at certain times of the year, as are blood worm, freshwater snails and mosquito larvae. If you reduce the normal daily feed of the pelleted diets, you will quickly see the Koi start to graze round the walls and floor of the pond as they sift through the Algae in search of live food.


How much and how often to feed?


Koi are Poikilothermic, which means their body temperature is governed by the surrounding water temperature. Therefore the amount of food they need or want to consume will vary with water temperature. They also have a very simple gut, not a complex stomach like humans and many animals, just one short, straight tube in which all the necessary 'goodness' in their diet must be extracted before being excreted. Only a limited amount of food can be properly digested at any one time, and the digestion process will slow down at lower temperatures. It is therefore very important to feed appropriate amounts of food of the correct protein levels at all times to ensure that maximum benefit can be derived from the food and avoid too much waste.


As water temperatures decrease, the protein level in the feeds should also be decreased, as this will aid digestion and avoid waste. As temperatures increase, the protein levels in food should also be increased as the Kois metabolism will increase and more protein will be required to maintain health and for growth.


Water temperature governs not only what type of feeds we use, but also how much food to give. At low temperatures, it is sufficient to feed only once per day, whereas at high water temperatures, Koi can be fed every hour. How much and how often can be open to debate, but a good basic rule of feeding is to feed wheatgerm foods, with a protein level of less than 38% at water temperatures of 58 deg F and below and to stop feeding all together when water temperatures fall to 46 deg F. Raise the protein levels in the food as the temperature increases, and also the number of feeds per day so that by high summer the protein level should be in the mid forties and the number of feeds can be up to around 8 per day.


Obviously this is a gross oversimplification of what is quite a tricky and controversial subject, as there are many food formulae and environmental conditions, stocking densities, and climate which will all play a part in this decision. A simple rule to follow when feeding Koi is that any food given should be consumed in less than 1 minute. If there is food remaining on the pond surface after this time your are probably overfeeding. So the rule is little and often. Large irregular feeds will result in poor digestion and take up of foods and massively increased waste in the water and your filters will have to work harder to cope. Small regular feeds will mean better digestion and assimilation of the food given, much less waste and massively improved growth. As an example of this we have conclusively shown that the same amount of the same food given over a set period in regular small feeds given via an auto feeder results in much more rapid growth rates in Koi than larger manually administered feeds given morning and evening only.

In very cold water temperatures, but with large ponds, feeding can continue down to somewhat lower water temperatures simply because there will be less temperature fluctuation in large bodies of water. In smaller ponds, the water temperature can dip as much as 2 or even 3 degrees overnight, typically in early Spring when we can have quite warm days followed by still bitterly cold evenings, and so you should cease feeding at around 48-49 deg F in small ponds to avoid this temperature trap. At very cold temperatures, the passage of food through the gut slows down considerably, and with a severe temperature swing, there is a risk that food can remain in the gut for far too long and start to rot, with disastrous consequences for our Koi.


If in doubt - don't feed - it is easy to kill Koi by overfeeding, but pretty much impossible to kill them by underfeeding.


We would also strongly advise that Koi feeding should be suspended whilst you go on holiday - this is infinitely safer than entrusting feeding your prize possessions to a friendly and well meaning neighbour. Holiday feeding is responsible for more Koi related problems than just about anything else! The Koi will find ample live food in the pond whilst you are away on holiday, and will not suffer whilst you are sunning yourselves in paradise.

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