Ten preventive measures to take during the peak growing season for adult fish

I. Prevent starvation. During the peak growing season, adult fish have a large food intake, so more bait and feed should be given. For ponds mainly stocked with grass carp, crucian carp, tilapia, etc., mixed feed such as wheat bran, oilseed cake meal and soybean dregs, as well as fresh feed such as tender grass and plant stems and leaves, should be given. Under normal circumstances, the daily amount of coarse feed accounts for 10% of the total fish in the pond.

II. Prevent fertilizer shortage. During the peak growing season, the amount of fertilizer required by fish accounts for 80% of the fertilizer to be applied during the whole period, so every 5 to 7 days, apply 60 kg to 100 kg of fully fermented human and livestock manure per mu, and 2 kg to 3 kg of nitrogen and phosphorus chemical fertilizer.

III. Prevent water temperature from being too high. The suitable growth temperature for fish is 23°C to 39°C. In hot seasons, to prevent the water temperature from being too high, new water must be added promptly. For a pond with a water layer of about 1 m, add 1/10 of new water every day.

IV. Prevent oxygen deficiency. In summer, fish consume a large amount of oxygen, and in addition the decomposition of large amounts of fertilizer and organic matter can easily cause oxygen deficiency. Therefore, aeration equipment should be installed. Where there is no aeration equipment, add new water at a ratio of 10% of the pond water, and at the same time supplement with artificial aeration.

V. Prevent gasping for air. Because the weather is hot and water pressure decreases, fish gather at the water surface to breathe, which is "gasping for air." Targeted measures should be taken according to the cause and severity of the gasping, for example, if the gasping is caused by a large amount of bait, increase oxygen promptly and add new water separately, and also use 6 kg of lime or 2 kg of alum or 2 kg of salt per mu, dissolve and splash it over the pond; remove all debris, residual grass, floating foam, etc. from the water.

VI. Prevent "water reversal." Water reversal, also called clear water disease, mostly occurs in sandy-bottom clear water ponds during excessively long rainy periods. What was originally a pond of fertilized water often becomes "clear to the bottom" overnight. The main reason is that there are many large zooplankton such as water fleas, cladocerans and copepods in the pond, which consume large amounts of phytoplankton, and in addition the amount of new water added to the pond on rainy days is too large, disrupting the ecological balance in the pond. The effective preventive methods are: increase the stocking of bighead carp and tilapia to control the number of zooplankton, splash with 9% trichlorfon crystal solution, and combine with artificial fertilization, and the pond water will soon become fertilized.

VII. Prevent water quality from aging. Because the temperature is high and fish grow fast, the pond water quality will change from slightly alkaline to acidic and age, seriously affecting the reproduction of natural food organisms, reducing photosynthesis and inhibiting fish growth. Every half month, use 20 kg of quicklime per mu, dissolve it and splash it evenly over the whole pond.