Ponds for fish farming have already been prepared, so the year's fish-farming work has to start now. How you prepare your pond at this time and what steps you take to renovate it will decide the year's fish yield. Some steps must also be taken now to prevent fish diseases.

Diseases of fry may appear right at the start of the season, such as sores on the body, black spot disease or white spot disease. The fry must be watched all the time, and treatment started as soon as symptoms are seen.

If fry have black spot disease, dip the affected fry for one hour in a solution of 3 mg of picric acid per litre of water. Then wash them in clean water and release them back into the pond. This will cure the black spot disease.

If fry have white spot disease, make a solution of 1 millilitre of formalin in every 5 litres of water and dip the fry in it for one hour a day for 7–10 days. The white spot disease will then clear up. Wash the fry in water and release them back into the pond.

If fry have sores on the body, dip them for 10 minutes in a solution of 1 gram of KMnO4 per litre of water, then release them into the pond.

Several diseases will also be seen in ponds of bigger fish at this time. Large numbers of argulus may infest the gills and body of the fish. To control them, apply a medicine called Nuvan to the pond at 130 millilitres per bigha. After applying it, drag a net through the pond several times to mix the medicine into the water. If the argulus are not controlled after 15 days, the medicine can be applied again at the same rate.

Bigger fish may also suffer from ulcer (wound) disease, rot of the gills and fins, or swollen-eye disease. To control these, mix 100 grams of either sulphazol acid or sulphazine into every kilogram of supplementary feed and feed it to the fish in the pond for 5–7 days. The fish will recover.

After that, apply lime to the pond at 13–20 kg per bigha. To purify the pond water, 650 grams of KMnO4 per bigha can be dissolved in water and added to the pond.

Citing: Agriculture Information Service.

Source: Jagonews24. First published in Bengali on The Agro News.