Reasons for guppies scurrying up and down:

1. A new environment. Guppies are relatively sensitive to changes in the environment. If they suddenly change to a new environment or if they are just bought home, they will move up and down.

2. Suffering from disease. It may be a disease, such as white spot disease, saprolegnia, gill rot, etc. After being sick, the guppy feels uncomfortable and will swim back and forth wildly.

3. In heat. When guppies are in estrus, they will swim up and down. This is a normal phenomenon. Keepers can observe whether the fish swimming up and down are all male fish.

4. Being chased by other fish. Because guppies are small and have a gentle personality, they are easily bullied by other fish. If other fish attack guppies, they will swim back and forth to avoid them.

5. The water temperature is too high. If the water temperature is too high and the tank environment is too stuffy, it will also cause guppies to move up and down. When raising guppies, the water temperature needs to be controlled between 22 and 24°C, and for juvenile fish, it needs to be controlled at around 24 and 26°C.

Solutions to guppy fish running up and down:

1. Create a quiet environment. You just need to maintain good water temperature and quality, pay attention to shading, avoid frightening, and wait for the guppy to become familiar with the new environment.

2. Symptomatic treatment. It is necessary to confirm which disease the guppy is suffering from and then treat it accordingly. You can first increase the water temperature and sprinkle salt in the fish tank. When the symptoms are severe, you can choose medicinal bath treatment with yellow powder, oxytetracycline, malachite green solution and other drugs.

3. Avoid mixed culture. Breeders can feed the two types of fish separately to avoid further injury to the guppies.