Fin rot. The fins of the black sawtail hanging fish are damaged and discolored, dull, and there are foreign objects in the rotten part. Or the transparent fin leaves turn white and gradually expand, and in severe cases, the fins are incomplete and cannot be stretched.

Treatment method: Dissolve 2 sticks of gentamicin in In a 200 kg fish tank, bath and disinfect. Or use 3 to 5 pieces of dysentery to dissolve in a 100 kg fish tank for bath disinfection. Usually need to pay attention to changes in water quality.