1.放养密度过大一是鱼类争食不均,容易形成强弱分化。二是水体环境恶化,极易发生缺氧泛池事故,爆发鱼病。2.品种搭配不当养殖品种搭配要考虑分层、分食问题,否则会造成饵料利用不均,缺食鱼类体弱多病,剩饵可败坏水质,污染池水。3.喂养不当投喂时要注意不投腐烂、变质、带菌物料 1. Stocking density is too large First, fish fight unevenly, easy to form the strength of differentiation. Second, the deterioration of water environment, prone to anaerobic pan-accident, outbreak of fish disease. 2. Varieties with improper breeding Breed to consider stratification, eating problems, otherwise it will lead to uneven utilization of food, lack of fish sickly, the bait can corrupt water quality, pollute the water. 3. Feeding improper feeding should pay attention to not rot, metamorphosis, carrier materials