There are two reasons that cause the clogging: long period of warm winter results in sudden growth of hydra in the filter; insufficient backwash rate fails to flush away the clogs.

• 造成堵塞的原因主要有两个:长时间暖冬导致了滤池中水螅的暴发性生长;反冲强度不够,不能冲掉堵塞物。