CKP Grow Your Koi

Established 1995

grow your koi

The size to which koi can grow is simply amazing. Jumbos measure at least 30 inches and weigh in at well over 30 lbs. The magical metre mark has also been broken in the gosanke variety

It is a great accomplishment for a koi hobbyist to grow a 4 inch koi into a 2 foot one. It means a healthy environment and proper care has been provided

On this page we will summarize the fundamental keys required to enable your fish to reach their growth potential. Although all the considerations are critical, they are arranged in descending order

1 - Genetics
Genetics are predetermine physical traits. So, now matter what is done to care for the fish, there is a predetermined size limitation and the goal is of course reaching that limitation. Most koi will reach an adult size of at least 20 inches if cared for properly

When selecting young koi, try to get a female with a larger head and frame. Knowing the bloodline is critical - big parents mean the chance for a big fish. Of course solid coloured fish such as Ogons, Chagoi and Magoi generally have the potential to grow larger than the more inbreed gosanke varieties

2 - Age
If you want to grow a large fish, you have to start the process from birth. It is critical to put the framework and size on in place in the first 2-3 years

3 - Optimum Water Quality
Water quality is pivotal. Everyone knows, we are water keepers not fish keepers. If there is a chronic measurable amounts of Ammonia and Nitrite you will not only hinder growth, but you can cause a disease state and even death. Excess Nitrates will also slow growth down. pH needs to be stable and oxygen saturation a going concern. Provide chemically clean water and your fish have the chance to grow quickly and reach their potential

left - mud ponds provide an abundance of food with lots of depth and swimming space. The sheer dilution factor alone ensures excellent water quality

4 - Water Temperature
Although koi can adapt to lower temperatures, their growth rate will suffer. Temperatures in the 25 degree celsius range will accelerate the metabolism and allow a tremendous amount of food to be fed. Although there can be a cooling down period for the fish in the Winter, this period should be short and not extreme. First year fish need to spend Winters in warm water indoors or their growth will suffer

5 - Provide the Nutritional Blocks
Even if you provide all of the above, without proper nutrition, fish will not maximize their growth. Consider 6 or more small meals per day as fish are grazers with less than efficient digestion

Because koi are heavily vegetarian their diet should include dark green leafy vegetables. The key words variety, freshness, nutrient content and frequency all apply

6 - House the Koi in a large deep pond
Obviously the pond dynamics are important. It is no coincidence that fish put on the best growth in low stocked high volume mud ponds. Large deep ponds allow fish to exercise and develop their musculature as well as provide lots of natural food

Although a smaller pond can be made to appear larger by installing jets, it is pretty tough to match the magic of a mud pond

Putting it all Together
As mentioned, these items are more like a 1a, 1b, 1c etc list because they are all so important. If you can incorporate all of the keys, there will be a synergistic effect and fish should put on great size quickly

1 year old Tosai can be over 16 inches and in successive years, 4 - 6 inches can be added. As the fish approach 5 years old, growth will slow to 1-3 inches a year

I once had a growing contest with one of my friends. We both had 35 gallon tanks and each purchased one 2 inch fish to grow. After 6 months, my fish was almost 8 inches while his was 3. I attribute this growth to my home made filter, weekly water changes, heating and the live tubifex worms which I fed 3 times a week. The difference in the fish was startling


This shot was taken in the April, a 8-9 inch tosai shiro utsuri earmarked for the mud pond		By November, the fish has grown considerably. Length and mass have increased and the fish displays great conformation		The fish was measured at 45 cm or 18 inches. That is an excellent growth rate of over over 1 inch per month as the fish grew about 10 inches in just 7 months

Last Modified : December 6, 2007
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