Previous - Next
In temperate climates when the water temperature reaches below 10°C, the overwintering season starts.
In Hungary near Budapest, this season lasts for about five months from November to March. Wintering ponds are relatively small (600 - 1 000 m²) and deep (2 m). Since common carp consume very little food below 10°C and stop feeding at 7°C, there is no food distribution in the wintering ponds.
90. The preparation of the wintering ponds involves several operations.
(1) The pond bottom is treated with lime (200 kg/ha) and the pond is filled with water. (2) The pond water is then treated with malachite green (5 mg/l) to prevent infections. (3) This chemical is progressively washed out and the fingerlings are stocked at the rate of 100 kg per 101/minute water inflow.
For example, 1 000-m² wintering ponds, 2 m deep, and equipped with an inlet pipe of 20 cm diameter, receive a maximum water inflow of 600l/min.
In such ponds a maximum of 6 t of fingerlings can be overwintered, which represents an average fish density of 3 kg/m³.
The necessary quantity of malachite green is dissolved in a bucket of water. (1) Half of this solution is poured close to the water inlet, the other half being distributed around the pond.
(2) Every day the dead fish are removed from the pond, if necessary using a grappling hook.
92. Every week, too, fish are sampled using a casting net.
Their health condition is checked by a specialized veterinarian.
Just as ectoparasitic infections predominate in warm conditions, bacterial and viral diseases are particularly common in cold water.
93. When ice covers the wintering pond it should be removed around the monk.
(1) A spreading plate is fixed under the water inflow to increase the oxygenation of the water.
It is important to keep these birds away from the ponds.
