1. Reason: Guppies suddenly can't swim, which may be caused by water quality mutation. Although they have low requirements for water quality, they are sensitive to environmental fluctuations. If the water quality suddenly changes greatly, they will be stimulated and affect their swimming.

2. Treatment: The breeder needs to adjust the water quality, keep the PH value between 7.2 and 7.4, and preferably control the hardness of water between 10 and 15. After they adapt to the new water quality, they can resume their previous swimming.

1. Reason: Guppies can't swim, which may also be caused by being frightened. They are timid and can be frightened easily. After being frightened, their activities will be stimulated, which will also affect their natural swimming.

2. Treatment: Breeders need to keep their living environment quiet, so that they can recover more quickly. After they recover, the breeder needs to raise the water temperature to 28 ℃, which can increase their activity.

1. Reason: The inability of guppies to swim may also be caused by illness. Common enteritis, water mold and white spot disease will affect their free activities.

2. Treatment: Breeders need symptomatic treatment according to their diseases. If it is bacterial diseases such as water mold and white spot disease, oxytetracycline can be used to give them medicated bath. If it is a digestive disease such as enteritis, the breeder can feed Xiaoshi tablets.