First, the swimming pool overwinters.
As the temperature drops, the surplus goldfish sold in autumn and goldfish raised as parent fish will begin to overwinter and enter the winter management stage. In winter, the water temperature is low, the fish activity is small and the oxygen consumption is low. For the convenience of management, goldfish are usually concentrated in deep pools or indoor greenhouses for winter. The time of merging ponds in the north is earlier, usually around the first frost; It is very late in the south, usually from heavy snow to solstice winter.
Before overwintering in the pond, we should first strengthen the cultivation in autumn, supply more live Daphnia to promote its growth and development, and accumulate protein and fat in the body to prepare for overwintering. At the same time, for parent fish, it is beneficial to the development of their gonads. The daily feeding time can be appropriately extended from 7: 00 am to 8: 00 am to 2: 00 pm. Secondly, fresh water should be injected before overwintering, because there will be a lot of goldfish feces and dirt deposition in the pool, and the water quality is already "old water". In addition, there is a layer of ice on the water surface in winter in the north, and the water is isolated from the air, which is easy to cause goldfish to die of hypoxia and suffocation. When injecting water, the water depth should be increased to about 80 cm, the surface layer is frozen, the water temperature in the middle and lower layers is still around 4℃, and the goldfish is basically dormant and rarely moves, so there is generally no big problem. In sunny and windless weather, dig out the surface ice on the south side to make the water contact with the air and replenish the dissolved oxygen in the water, so as not to lack oxygen. After snowfall, it is necessary to clear the snow on the ice layer to avoid insufficient photosynthesis of plankton and lack of oxygen in the water body.
Finally, we should pay attention to timely and reasonable stocking. The water temperature during stocking is 5℃ ~ 10℃. If the pool is merged too early, the water temperature is too high and the wintering density is high, which is easy to make the water turbid and cause hypoxia. If you swim too late, goldfish will often catch a cold and get sick. Generally, the overwintering stocking time should be before freezing and the stocking density can be higher. Calculated per square meter, large goldfish with body length 15 cm ~ 20 cm can be stocked12 ~15; Goldfish with body length 10 cm ~ 15 cm can raise 45 ~ 60 goldfish; When the body length is 5 cm ~ 10 cm, 75 ~ 100 goldfish can be raised. When swimming in the pool, fish should be fished lightly. At this time, the water temperature is low, and once the goldfish is injured, it is difficult to recover. During the winter, it is easy to get sick with bacteria, such as swim bladder disorder, Dendrolimus disease and so on.
Second, overwintering outdoors
Goldfish can also overwinter outdoors, and the survival rate can reach more than 90% as long as it is properly managed. Outdoor wintering must choose deep pools, and the water depth is generally more than 2 meters, such as reservoirs and earthen pools. In the specific operation should pay attention to the following aspects:
1. pool cleaning and disinfection. Clean up the pond in advance, dig out the mud at the bottom of the pond, sprinkle quicklime water to kill enemy creatures, inject new water after the toxicity disappears, and then put the fish into the pond.
2. Reasonable stocking. The stocking time should be about 5℃, and it is best to choose sunny noon. Free-range fish must be healthy fish, with strong physique and no disease or injury. Stocking density should not be too high. Goldfish wintering outdoors live under the ice, and the gas in the water cannot be exchanged with the outside world. Generally, only 5 to 8 goldfish can be kept per square meter.
3. Strengthen management. Sweep snow and ice frequently on sunny days, increase dissolved oxygen in water, and prevent man-made damage. Goldfish wintering outdoors have stronger disease resistance than goldfish wintering indoors, and can withstand the weather with large temperature difference in the coming spring.
Third, wintering indoors.
When the water temperature is around 10℃, the goldfish will be moved into the indoor pool for the winter. The fish pond is filled with fresh water first, and the stocking density is 2 ~ 3 times higher than that of outdoor autumn culture. The water temperature can be kept at 2℃ ~ 10℃ all winter. When the water temperature is high, a small amount can be fed, and the dirt at the bottom of the pool can be sucked with a straw every few days, and then an appropriate amount of new water is slowly injected, and the temperature difference should not exceed 2℃. Indoor wintering is characterized by high survival rate of goldfish, which can generally reach more than 95%.
Fourth, the greenhouse overwinters.
Fish ponds with good conditions have glass or plastic greenhouses for goldfish to overwinter. Because the greenhouse can receive sunlight well, the heat preservation effect is good. When the outside water temperature drops to 15℃, the water temperature in the greenhouse can reach 25℃, and goldfish can eat and grow normally after entering the room. Attention should be paid to the following aspects in greenhouse wintering:
1. Prepare the greenhouse. The goldfish room should face south, with the leeward facing the sun, light and heat preservation. There should be heating equipment indoors to facilitate water supply and power supply. Prepare a grass curtain or cotton curtain that can be lifted freely, so that it can be lifted at night and morning to keep out the cold at night and light and warm during the day.
2. Feed correctly. When the water temperature in the greenhouse is suitable, you can feed more and change the water frequently. When winter comes, the water temperature drops below 16℃, feed less and change the water frequency appropriately. In the early spring of the following year, when the water temperature rises above 16℃ again, the goldfish in the greenhouse will enter the spawning estrus, which is 20 ~ 30 days earlier than the normal spawning time. According to the management of cultured fish, goldfish can lay eggs in advance, and goldfish can also move into outdoor culture. The characteristic of overwintering in greenhouse is to shorten the overwintering period of goldfish, and goldfish can still eat and grow in greenhouse and reproduce in advance.
3. Strengthen management. Give priority to cold and warmth, feed properly, and try to keep goldfish not thin and sick. Throughout the winter, under the premise of ensuring the safety of goldfish, try to reduce the operation of changing water, adding water and cleaning goldfish. Change the water once a month and clean the goldfish every 3 to 5 days. During operation, fish should be fished less and touched less to prevent fish from being damaged, bleeding and scaling, prevent the spread of water mold and white spot disease (goldfish suffering from this disease is difficult to treat), and avoid causing greater losses.