The period from March to May of each year is the peak of hatching of all kinds of fish fry. This period has higher requirements on water quality, water temperature, and predator biology. If there is a problem on one side, the whole incubation process will fail. Therefore, special attention should be paid to the following aspects during fry hatching. 1. Water quality The fresh water for fry hatching requires fresh water, non-toxic, non-polluting, adequate dissolved oxygen, moderate pH, and invincible pests. 2. The water temperature should be moderate Generally, the incubation temperature of fry is required to be between 20 ~ 30 °C. This time is more vulnerable to cold wave attack. When the weather is cold and hot, it is easy to freeze the fish eggs or be infected with water mildew, causing fry hatching. failure. Therefore, during this period of time, special emphasis should be placed on preventing cold and warming and preparing warming equipment. 3. Elimination of predatory organisms The removal of hostile organisms in water can be eliminated by filtration equipment or by means of drugs. Incubation water is generally filtered through a 70- to 80-mesh nylon sieve or other mesh equivalent to this specification. Due to the long filtering time, the accumulation of predator organisms and impurities will directly affect the filtering effect, so it is necessary to regularly remove debris and replace the filter. It is best to configure a reservoir to allow the filtered water to flow into the reservoir for storage. This will facilitate the use of drugs and kill the enemy water organisms such as sword leeches and leeches. Kill water and other harmful organisms such as water, per cubic meter of water can be used 2.5% of trichlorfon powder 1 g splash hatch water, or per cubic meter of water with 90% crystal trichlorfon 0.1 g Quanchiposa. When using trichlorfon to kill harmful organisms in the water, some fish are more sensitive to trichlorfon, such as freshwater and white fleas. Potassium permanganate may be used to splash water for incubation, and the dosage is high for every cubic meter of water body. Potassium manganate 5 grams, dissolved in water after hatching, can remove water blisters in water. 4. Disinfection of Incubation Appliances Hatching fry utensils such as mesh, barrels, pots, etc. can only be used after disinfected with potassium permanganate or chlorine dioxide.