清塘时间以在放养鱼苗前半个月左右为宜,如清塘过早,药效消失后,害鱼和病原菌又将重生;过迟,则毒性未退,影响鱼苗的放养。为了安全起见,药物清塘后,最好先试养几条鱼,证明毒性确已消失,才可大量放养鱼苗。 1.生石灰清塘法。生石灰化水后成为强碱氢氧化钙,能杀灭害鱼、 Clear pond time to stocking fry about half a month is appropriate, such as clear pond too early, after the disappearance of efficacy, fish and pathogens will again be born again; late, the toxicity has not retreated, affecting the stocking of fry. To be on the safe side, after clearing the ponds, it is best to try out several fish first to prove that the toxicity has indeed disappeared before you can stock a large number of fry. 1. Lime clear pond method. After lime water becomes a strong alkali calcium hydroxide, can kill fish,