Detailed Explanation of Key Points and Management Methods for Koi Breeding Technology
Biologically, koi belong to the Cyprinidae family, which is the largest family among all fish species, with more than 1400 species. It is a high-grade ornamental fish popular around the world today, praised as the “living gem in the water” and “swimming artwork”. Because it has low requirements for water quality, is omnivorous, and reproduces easily, it is welcomed by people.
Selection of Koi Breeding Sites
Whether koi are raised by gardens, fish farms, or individual specialist households, the establishment of koi breeding sites, water sources, and power sources must have unified short-term or long-term planning. Even koi enthusiasts building a few small fish ponds in a courtyard should design according to local conditions. This is because the selection and planning of koi breeding sites and water sources can directly affect the growth and development of koi and future scientific and technological management, so a comprehensive investigation and plan must be made in advance.
1. The fish farming site should preferably be chosen in a place with sufficient sunlight and good ventilation, especially a suburban area, courtyard, reinforced rooftop, or balcony that can receive sunlight between 6 a.m. and 12 noon and also has good ventilation conditions.
2. The fish farm must be close to water and power sources. If the water quality of rivers, lakes, and streams is not polluted, in order to reduce fish farming costs, natural water sources can also be used according to local conditions, and after being drawn in and treated in a filter pond, it can be used. If the water quality of rivers, streams, and lakes is polluted and groundwater (deep well water) or tap water must be used, then the fish farm should be chosen in a place with a relatively high groundwater level or near a place where tap water pipes can be connected.
3. The fish farm should be chosen in a place with convenient transportation. If it can be close to an airport, station, or ship dock, that is most ideal. In this way, the advantages of transfer or transportation can be brought into play. It can not only reduce export transportation costs, but also play a very positive role in increasing the survival rate of koi during transportation.
4. The fish farm should be close to feed production areas. Only with sufficient feed can koi be raised well. If food is lacking, koi will become ill due to physical constitution problems.
Construction and Reasonable Layout of Koi Breeding Ponds
At present, the construction of domestic koi breeding ponds can be roughly divided into three types:
1. Productive koi ponds far from urban areas with relatively large breeding areas. The largest of this kind of koi pond can reach more than 10 sq m. The pond depth is about 35—50 cm. In recent years, for the Ranchu koi raised in Fuzhou, Guangzhou, and Dongguan, fish farms will build the ponds deeper in order to make the fish grow larger, generally with water depth reaching more than 50 cm or even deeper.
2. Breeding ponds in fish farms used for both ornamental and production purposes. The ponds in these fish farms must meet both production and ornamental needs, so the pond area should be smaller and shallower, generally about 3—5 sq m, with a depth of about 25—35 cm. This is commonly seen in parks.
3. Household breeding ponds. Due to limited conditions, regardless of the size, shape, or orientation of the pond, it should be adapted to local conditions, and there is no need to excessively insist on standardization. Therefore, some koi enthusiasts use just one brick placed upright, (about 25 cm high), with cement bonded and plastered in the middle to form a small pond (about 1—2 sq m) for raising fish, which is quite economical, convenient, and practical. Whether productive, ornamental, or household, the walls of the pond should not be too high. A water depth of generally 30—50 cm is better.
Management of Koi Breeding Ponds
Before and after koi enter the venue (home), preparation must be made when introducing koi, which is of very important significance to whether the koi can survive and quickly adapt to the environment of the site:
1. New ponds should be filled with water and soaked. For a newly built fish farm, the pond should be filled with water and soaked 15—20 days before the koi arrive. This achieves the purpose of removing alkalinity and “reducing fire”. The soaking time is best about 1 week. If the new pond is needed urgently, two methods can be used: The first is to dissolve 12-15 grams of phosphoric acid in 50 kg of water, put water in the new pond and soak for 1-2 days, which can achieve the purpose of removing alkalinity. Drain the water containing phosphoric acid, then rinse and disinfect with salt water or potassium permanganate solution, fill with old green water or clean water and soak for about 1 week to promote the early growth of algae, then again refill with fresh water and expose to the sun for 3—5 days. After dechlorination, koi can be put into this pond water for breeding. The second is to add alum to the soaking water of the new pond (about 250 grams per ton of water). After 2—3 days, it can also achieve the purpose of removing alkalinity, then add green water as above and soak for several days, then inject fresh water and expose to the sun for 3—5 days. After dechlorination, this pond can be used for raising fish.
2. Disinfection of koi breeding ponds. Even for an old fish farm, if fish have not been raised for a long time or the pond has not been used for raising fish at the end of winter, it is best to soak and disinfect with 2%-3% concentrated salt water or 10—20 mg/L potassium permanganate or trichlorfon solution before use. The purpose is to check whether the pond has freeze cracks and leaks after overwintering and to prevent fish diseases.
3. Household fish breeding. For household fish breeding, the purchased yellow sand tank or ceramic tank should also be soaked to reduce fire and disinfected, then put into concentrated green water and soaked for several days (the purpose is to accelerate the growth of algae). Finally, replace with new (fu) water before fish can be raised.
4. Temporary holding. After the introduced koi have been transported, especially after long-distance jolting, the protective layer (mucus) on the fish body surface is easily damaged by abrasion. Therefore, before the golden fish arrive at the site (home), several tanks or large basins or 1—2 small fish ponds should be prepared at the site (home), filled with 1/2 pond (tank) of fresh water. After the purchased fish arrive, first put them into the tank, basin, or small pond, bathe them in 1%-2% salt water or 10—20 mg/L nitrofurazone or 5-10 mg/L potassium permanganate solution for 5—15 minutes (the time should be flexibly controlled according to the size of the fish), then put them into the breeding pond to rest quietly (if there is green water, it is best to mix a little into the pond), and add nitrofurazone powder to the breeding pond at a ratio of 2—3 mg/L, thereby reducing the incidence of fish diseases. Never pour the water from the original plastic bag after long-distance transportation directly into the breeding pond.
5. Feeding. Koi should not be fed on the first day after entering the venue, and should be fed little or not at all on the second day. The subsequent feeding amount should follow the principle of gradually increasing according to the appetite of the koi. This helps prevent the water quality from deteriorating easily and allows it to quickly turn green. Never overfeed at one time and spoil the water quality. This will ruin a pond of new water and seriously affect the health of the koi.
6. Disinfection of breeding utensils. All utensils used, such as fish worm nets, fish nets, fish basins, brushes, rags, suction pipes, and all other tools, should be disinfected, sun-dried, and hung in a fixed and dry place. Do not throw them around.
7. Installation of aeration equipment. Where conditions permit, the fish farm can install an aeration pump in the koi pond just after the koi enter the venue to increase oxygen, so that the koi can quickly recover their strength after transportation.