I. Pond Preparation
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LocationChoose a site with ample water supply, convenient water inlet and drainage, no pollution, and good transportation access. This facilitates water management and the transport of fry, feed, and mature fish.
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Water QualityThe best water sources are unpolluted rivers, lakes, or reservoirs. Alternatively, water from self-drilled wells can be used, provided it meets fishery water standards and is free of toxic or harmful substances.
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AreaThe pond area should generally be 1–5 mu, with a maximum not exceeding 8 mu. High-yield ponds should be equipped with 1–2 aerators, each with a power of 1.5 kW.
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Water DepthThe water depth of the rearing pond should be 1.5–2 meters.
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Soil TypeThe soil should have good water retention, fertility retention, and insulation properties, and should support the cultivation and proliferation of plankton. Based on experience, loam soil is best, followed by clay, while sandy soil is the least suitable.
II. Stocking Density
Stocking density should be adjusted based on the size of the earthen pond, water volume, water temperature, aeration conditions, the size of the koi, and their growth status. Specific references can be made to Table 3.
Table 3: Stocking Density of Koi in Earth Ponds
|
Earth Pond
|
Koi
|
||
|---|---|---|---|
|
Area (m²)
|
Depth (cm)
|
Body Length (cm)
|
Quantity (fish)
|
|
3.3
|
30~60
|
12~15
|
20~30
|
|
25~30
|
5~10
|
||
|
5
|
30
|
12~20
|
10~15
|
|
10
|
30~60
|
~30
|
15~20
|
|
50~100
|
10~20
|
||
|
15~20
|
50
|
15~20
|
30~40
|
|
30
|
10~20
|
||
|
20~30
|
50~100
|
~30
|
20~30
|
|
40~50
|
50~60
|
<30
|
30~40
|
|
60~100
|
>30
|
~20
|
|
|
100
|
50~100
|
<30
|
~50
|
|
>30
|
30~40
|
||
|
200
|
70~130
|
30
|
60~100
|
|
45
|
40~50
|
||
|
60
|
20~30
|
(Not specified)
|
III. Feeding
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Feeding QuantityFirst, feed approximately 1/5 of the koi's body weight, divided into several feedings. Second, set up feeding platforms according to the koi's feeding habits and appetite. Follow the principle of feeding small amounts multiple times, placing the feed on the platforms. Any leftover feed should be removed at night to prevent water pollution.
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Feeding TimeGenerally, from April to September, feed once with water fleas before 7:00 AM. In other months, feed water fleas around 9:00 AM. Additionally, live snails can be added in slightly larger quantities, as any uneaten snails will remain in the water and feed on algae and debris attached to the pond bottom and walls, helping to clean the pond water. They serve as excellent supplementary feed. If compound feed is used according to the above schedule and the feed on the platforms is consumed, a small additional amount can be provided. Repeat as needed, and remove any leftovers at night.
IV. Daily Management
The saying "three parts rearing, seven parts management" highlights that management is more critical than rearing itself. The operational techniques in koi rearing can be summarized as "careful, gentle, cautious, and attentive."
(1) Monitor the cleanliness and hygiene of the pond water.
(2) Observe the dissolved oxygen levels in the pond water.
(3) Measure the physicochemical indicators of the pond water.
(4) Observe the activity and feeding behavior of the koi.
(5) Check the vitality, respiration, and feces of the koi.
(6) Inspect the body surface of the koi.
In summary, the daily management of koi is a highly technical task that must be performed diligently and consistently.
