- Lack of oxygen: Bettas need a well-oxygenated environment to breathe. If the water in your tank is low in oxygen, your Betta may swim at the surface to get more air. Increase water aeration or add plants that produce oxygen.
- High ammonia or nitrite levels: Bettas are sensitive to high levels of ammonia and nitrite in the water. These compounds can cause health problems like respiratory distress and affect the Betta’s ability to breathe properly, making them swim at the surface to gasp for air. Test water quality and do water changes accordingly.
- Extreme temperatures: The ideal temperature range for Bettas is 76°F to 82°F (24°C to 28°C). Water that is too cold can make them lethargic and more prone to catching illnesses, causing them to float near the surface. Water that is too hot can also distress the fish and cause it to swim erratically in an attempt to find cooler water.
- Stress: Stress from factors like overcrowding, improper tank setup, sudden water changes, or bullying from other fish can also lead to this behaviour. Bettas are more prone to stress than most other fish due to their wild counterparts being found in shallow rice paddy fields rather than rivers and lakes. Create a peaceful and comfortable environment for your betta to minimize stress.
- Disease or illness: Some diseases and illnesses, like swim bladder disorders or infections, can also cause your Betta to swim at the surface. If your Betta is showing any other symptoms of illness, it is important to take them to a vet for diagnosis and treatment.
Keep in mind that occasional surface swimming is normal in Bettas. If your Betta is constantly swimming at the surface or exhibits other abnormal behaviours, it's important to address the underlying cause. Regularly monitoring your water conditions, providing proper temperature, creating a stress-free environment, and ensuring good water quality will help keep your Betta happy and healthy.