I have 75g tank with shubunkin and koi fish of size hardly 3"

I have a large showa koi fish. I have had this koi fish for 12 years. It is about 20 inches long, and it is beautiful. I am writing because it now has a large open wound (about the size of a nickel) on its side, which it inflicted on itself in trying to jump out of the fish pond. I do not know how to treat it.

What are the three factors that will determine the size of your koi and goldfish?

It is also important to consider what size the fish can potentially reach. The three 6-inch koi you bought two years ago have a tendency to get bigger very quickly, which means you’ll need a bigger tank or fewer koi in the one you have.

Also, the size of your butterfly koi fish will help determine its age

Sizes :Large Koi Fish Food - 7mm : 32 oz.Large Koi Fish Food - 7mm : 5.4 lb. Watch how a great blue heron swallows a huge koi fish partly in slow motion and compare the size of the koi fish with the heron head, unbelievable.

Most Koi fish winter tanks are 100 to 1,000 gallons in size

Consider the size of the Koi in comparison to any other Koi the shopper already has. Koi have voracious appetites and eat anything they fit into their mouths. Therefore, purchasing a very large Koi to place with smaller fish, or purchasing small Koi to live with larger Koi is unwise. Overstocking leads to water quality issues and can result in disease and general ill health. Therefore, before purchasing Koi, consumers must ensure their pond or and can cope with the additional fish. To help new fish adjust to their new surroundings, the addition of water treatments, such as calming treatments and general health tonic is advisable.

The length of a koi can average up to about 3.28 feet

The Koi is a carp that was selectively bred originally in Japan for desirable colors. Koi can get to be very large with 2 feet plus being a common size for adult fish. Because of their large size Koi are pond fish and they do best in large outside ponds. Each fish needs several hundred gallons of water to adequately care for them. A common mistake is to buy too many fish for your pond. While young, the volume of water in the pond may be fine, but as these fish grow they will need larger volumes of water to prevent growth stunting.Koi fish can grow really, really big. The size they can grow to is determined by various factors, especially the environment they live in. If their habitat is well maintained, koi can grow quite large and also a lot healthier, living anywhere from 25 to 30 years. Exceptional koi can live for well over 100 years and the foundation on which everything else is built is a proper-sized pond.There are many different varieties of koi fish that vary in color, size, pattern, and type of scales. Simply put, koi fish are one of the most beautiful pond fish available. They have become so popular in the past century that they can now be found in ponds all across the world.Overall, the Koi is a fantastic fish for the properly sized pond. Keeping them in climates where it drops below freezing or gets above 90 °F (32 °C) for extended periods of time will be difficult. If you do live in an area like this, you will need a deeper pond, that is if you're even able to have one.