Tilapia overwintering or try water heater heat preservation

Guangdong enters autumn overnight, and the temperature in the past 10 days has been kept at about 21-28 ℃. The climate is comfortable and pleasant. As the temperature dropped, the streptococcal disease of tilapia, which had been rampant in the past two months, began to stop, and farmers breathed a sigh of relief. However, as the so-called "autumn wind cool", as the temperature continues to drop, tilapia autumn and winter heat preservation work can not be slack.

Heat preservation and water quality of water heater are easy to control.

The living temperature range of tilapia is 15-35 ℃. Tilapia is dormant when the water temperature is below 15 ℃. It is understood that the current ways of overwintering farmed tilapia are natural overwintering, greenhouse overwintering and groundwater insulation overwintering and so on. Groundwater thermal insulation can keep the water temperature above the critical value all the year round, but it is only suitable for places with groundwater resources, which has limitations. Under the condition that there is no extra cold wave and the water temperature in winter is not lower than 10 ℃, the natural overwintering method is widely used. However, after a large number of dead fish after the 2008 freezing disaster, most farmers no longer dare to take it lightly. Of course, in order to be foolproof, building a greenhouse to survive the winter is the safest way, but the cost is relatively high, so at present, the greenhouse is mostly limited to fish fry ponds and parent fish ponds.

"you can consider using a hot water stove to keep warm," Liang Cong, general manager of Guangzhou Wulonggang Fisheries Development Co., Ltd., told the reporter. In the South China Sea area of Foshan, many California perch breeding ponds and fish fry ponds use hot water stoves to keep warm through the winter. There are also fish fry farms that do early fry in spring and use hot water stoves to heat up their eggs. He has made an on-the-spot investigation on this, and feels that this way of overwintering is effective and economical, and he also plans to build a hot water stove to heat it up in his fry farm.

"I think the heat preservation method of water heater is very suitable in Maoming area, and it is also applicable in Guangdong as a whole," says Liang Cong. Maoming is located in the southern part of Guangdong, where the water temperature is relatively high (mostly above 11-12 ℃), and there is not much time for extremely low temperature in a year. "if you only need to heat up 20 days to a month in a year, just keep the water temperature above the critical value of tilapia," so the fuel cost is not high.

"because the greenhouse is an airtight environment, it is difficult to control the water quality, while the water heater does not have this problem." Liang Cong says that the hot water stove burns whenever it is used and communicates smoothly with the outside air, while once the greenhouse is covered, it will not be dismantled until April or May next year. In this way, for as long as several months, there is basically no air exchange with the outside world in the greenhouse, and the humidity, fog and dissolved oxygen in the greenhouse are also very problematic. In addition, the feeding pollution, nitrite and ammonia nitrogen are on the high side, and the water quality is very difficult to regulate and control. It's easy to cause disease.