Detailed Explanation of Key Technical Points for Efficient Loach Pond Aquaculture

I. Aquaculture Conditions

The aquaculture site should, as far as possible, be close to a water source with fresh, pollution-free water quality and convenient water intake and drainage. The soil should be neutral or slightly acidic clay soil, with ample sunlight, convenient transportation, and a guaranteed electricity supply. The aquaculture pond should be rectangular, with an area of 2-3 mu, a pond depth of 0.7-1 m, and a water depth of 0.5-0.6 m. The pond walls should be made of compacted soil. Mesh netting should be installed around the inner perimeter of the pond, with the lower edge buried in hard soil and the upper edge extending 20 cm above the water surface, which can effectively prevent loaches from escaping and prevent harmful organisms from entering. A 15-20 cm thick layer of fertile mud should be spread on the pond bottom. The water inlet should be 20 cm above the water surface, and the water outlet should be set at the bottom of the pond and kept sealed under normal conditions. Both the inlet and outlet should be fitted with wire mesh to prevent escape.

II. Stocking Models

1. Preparation before stocking: 10 days before stocking loaches, clean and level the loach pond, plug any leaks, clear the intake and drainage pipes, till the sludge at the pond bottom, and then disinfect the pond with quicklime. For each mu of pond with a water depth of 10 cm, use 70-80 kg of quicklime, slake it into a slurry, and immediately splash it evenly over the entire pond. Three days after pond disinfection, add water to a depth of 30 cm, and apply 50 kg of dry chicken manure per mu, evenly scattered in the pond, or place 100 kg of pig, cattle, or sheep manure in a concentrated pile in the fish pit to let it ferment and decompose. Afterward, apply fertilizer as appropriate depending on whether the water is too rich or too lean. The water transparency should be about 20 cm, such that the mud at the pond bottom is not visible.

2. Fry stocking: In April, when the water temperature rises above 15°C, stocking can begin. Stock 1000-1500 kg per mu of fry with a size of 70-80 fish per kg, or 800-1000 kg per mu of fry with a size of 100-120 fish per kg. Before stocking, disinfect the loach fry with 3-5% saline solution for 5-10 minutes. The loach fry stocked in the same pond should be uniform and consistent in size. The specific stocking amount should be flexibly determined based on factors such as pond and water quality conditions, feeding management level, and planned harvest size.

III. Daily Management

1. Feed feeding: When the water temperature is above 15°C, the appetite of loaches gradually increases; at 25-27°C, their appetite is particularly strong; when it exceeds 30°C or falls below 12°C, feed should be reduced or even stopped. When the water temperature is below 20°C, plant-based feed should dominate, accounting for 60-70%; when the water temperature is 21-23°C, animal and plant feeds should each account for 50%; when the water temperature exceeds 24°C, plant-based feed should be reduced to 30-40%. Animal-based feeds for loaches include animal viscera, earthworms, and small trash fish. Plant-based feeds include soybean meal, rapeseed meal, wheat bran, and grains. Generally, feed once each in the morning and afternoon, with a daily feeding amount of 4-10% of the loach's body weight. The feeding amount should be flexibly adjusted according to water quality, weather, and feeding conditions, with the standard being that no leftover feed or only a slight amount of leftover feed is seen by the early morning of the next day. Feeding should be carried out at fixed times, fixed locations, with fixed quality, and fixed quantity. Generally, loaches can be harvested after about 4 months of culture. If market conditions are good, they can be harvested earlier, and then the next batch of loaches can be stocked.

2. Water quality regulation: The quality of the pond water is extremely important for the growth and development of loaches. The preferred water color of the pond is yellow-green, and the transparency should preferably be 20-30 cm. When the water color turns tea-brown or dark brown, or when the dissolved oxygen in the water is below 2 mg/L, new water should be added promptly and part of the old water replaced to increase dissolved oxygen in the pond water and avoid stress reactions in loaches. Usually, fertilize once every 15 days, applying about 15 kg of organic fertilizer per mu each time. Depending on the specific water color, 1.5 kg of urea or 2.5 kg of ammonium bicarbonate can also be applied per mu each time to maintain the pond water in a yellow-green color.

IV. Key Measures

The main task is to strengthen pond patrols, patrolling 3 times a day in the morning, noon, and evening. First, check the embankments, plug leaks, maintain the water level, and prevent floating head and pond turnover; second, observe the feeding, activity, and disease occurrence of loaches, promptly clean the feeding area, and remove leftover bait; third, prevent snakes, ducks, and other animals from entering the pond and harming the loaches; fourth, regularly use organic fertilizer to keep the pond water fertile, lively, and refreshing; fifth, build shade shelters over the fish pit in summer, and overwinter with shallow water or by draining the pond in winter. From June to October, disinfect with chlorine dioxide once every 2 weeks, splash quicklime over the entire pond once a month, and also use microecological preparations as appropriate. During hot and stuffy weather, low air pressure, thunderstorms, or continuous rainy days, pay attention to observing whether adult loaches are floating to the surface. If floating head is severe, promptly add new water, and keep aquaculture records.