大多数鱼病的发生都在４～１０月这段时间流行。因此，掌握鱼病的发生规律，针对不同鱼病的发生季节，在鱼病发生前定期进行药物预防，对控制鱼病的发生会起到很好的作用。 １．体外鱼病的药物预防　主要采用全池遍洒法。预防体表细菌性疾病，常用漂白粉，使池水成１毫克／千克 Most fish diseases occur in the period from April to October. Therefore, to grasp the occurrence of fish diseases, for different seasonal occurrence of fish diseases, regular prevention of fish diseases prior to drug prevention, control of the occurrence of fish diseases will play a good role. 1. In vitro drug prevention of fish disease is mainly used throughout the pool sprinkling method. Prevention of surface bacterial disease, commonly used bleach, the water into 1 mg / kg