Having a Koi fish and watching them feed is one of the most interesting things to do. Koi fish can be trained to come to the surface and accept food directly from your hand. Koi need nutritionally balanced food for their growth and proper body functioning as well as for their immunity.
The quantity of food and the frequency of feeding will depend on the size and age of the fish as well as the season of the year. A Koi feeding chart will guide you to know the amount of food to feed your fish as well as the number of times.
Generally, koi will eat more when the temperature is high but they will eat less when the temperature is low and can even go without food at extremely low temperatures.
The Feeding and Growth Rate of Koi
The feeding and growth rate of koi depends on many factors such as their genetic background, water quality as well as the stocking density. However, one of the most important factors is the water temperature.
They are cold-blooded like every other fish which means that the temperature of the water is what influences their own body temperature.
At high temperatures, their metabolism increases, and they require more food. But at low temperatures, they conserve their energy and require a lesser quantity of food.
Koi growth rate is rapid when they are smaller and even more obvious in the warmer seasons during summer when they eat more food. But as they grow older, they will convert most of the energy from the food they eat for reproduction. The male produces sperm while the female produces eggs in preparation for breeding.
Nutritional Requirements of Koi
The nutrient composition of a koi fish must be balanced. That is, it must contain the required nutrients in the right proportion for their growth and immunity.
Koi are omnivorous and they will readily accept food that is either plant-based or animal-based. However, for you to choose the right food for your koi you must consider their size and their stage of development to match the food with their nutrient requirement.
They need all the classes of food to function properly. They need energy food like carbohydrates to supply them with the energy that they need to swim, look for food, and even reproduce.
They also need protein for growth and repair of worn-out tissues and maintenance of normal bodily functions. The fat in their nutrient serves as a store of energy which is important for them especially when the temperature is low and they won’t be able to eat much.
Vitamins and minerals are essential for proper bodily function and they are also needed for the bright coloration of the fish.
You can either feed your koi with floating or sinking food. They prefer sinking feed because the position of their mouth is best suited to pick food from the bottom of the pond. However, you can also train them to accept food from the surface.
The advantage of floating feed is that it lets you see the fish when they are coming up to get the food. You can observe them as they feed and you can easily tell if they are doing fine or not.
One of the things that most people rearing koi enjoy is watching them feed directly from their hands. When you give them floating food they will come to the surface to feed and with time they will recognize you and take food directly from your hand.
Also, there are other advantages of feeding floating food. You can easily tell when they have had enough food and you can stop feeding them. The best practice is to feed your fish with enough food that they can finish in 5 minutes. Feeding them too much will waste the food and it can pollute the water and cause stress to the fish.
However, their natural habit to feed on the bottom of the pond, it is best to mix floating feed and sinking feed so that they can eat some from the surface and feed on the bottom of the pond.
Feeding Requirement Of Koi Based On Temperature
The temperature of the water will affect the feeding of koi more than any other factor. They are cold-blooded and the temperature of the water affects their body temperature.
When the temperature drops, their metabolism reduces as well as their ability to digest food. Also, the frequency and quantity of feeding will reduce when the temperature is low. The type of food they need during cold weather is the type that can easily digest.
Foods that are high in protein take a longer time to digest so you should reduce the protein content during cold weather and add more cereal-based diets that they can easily digest.
When the temperature increases and their metabolism increases, they will need more protein-based food for growth and maintenance of their bodily functions.
Below are the feeding requirement based on the different temperatures of the water.
At a temperature of 72 – 80 F, you can feed your fish about 3 – 4 times a day. You can feed them with food that has a high protein content of up to 40% crude protein. You can also add extra foods such as vegetables, fruits, and algae as treat.
When the temperature drops to 65 – 72 F, you can feed them 1 – 2 times a day. You can feed them with protein by up to 35%. You can also add supplements such as fruits and vegetables.
As the temperature drops to about 60 – 65 F, you need to reduce the frequency of feeding to just once in a day. You should also reduce the quantity of food that you give them at this temperature.
The temperature continues to drop as you are getting closer to winter. At about 55 – 59 F, you have to reduce the number of times you feed them in a week. You can skip one day or two days a week and feed them 5 – 6 times and also reduce the protein content of their food to about 25%.
At the low temperature of 50 – 55 F, you should only feed your fish 2 – 3 times a week. And if you need to add an additional supplement, let it be food high in carbohydrate and low in protein. For example, wheat germ and brown bread.
And finally, you should stop feeding when the temperature is less than 50 F. At this temperature, their metabolism is so low that they don’t need extra food. They will feed on algae in the water if they are hungry.
Feeding Requirement of Koi Based on Their Size
In addition, the type of food that you will feed to your koi will also depend on their size. Bigger koi should be fed with pelleted feed while smaller ones can be fed with flakes.
If you feed the bigger fish with a small food size, they will need to spend more energy going after the food. It will also take time for them to pick the food and some food particles may dissolve in water in the process and pollute the water.
You can vary the size of food you give your fish if you have smaller and larger fish in the same pond. At 6-8 inches, the amount of feed they will require will be equivalent to 5% of their body weight. And as they grow longer to over 8 inches you can reduce it to 2% of their body weight.