There are several reasons why bettas might stop eating. Below are common causes and their corresponding solutions:
Environmental Adjustment Issues
Newly introduced bettas may experience stress from transportation or changes in their surroundings, leading to refusal to eat. It’s advisable to let them rest quietly for 3–5 days, with reduced light and disturbances.
Water temperature fluctuations: As tropical fish, bettas thrive in water temperatures between 22–28°C. If the temperature drops below 20°C or fluctuates drastically, their appetite will decrease. Use a heater to stabilize the temperature at 24–26°C.
Water Quality Problems
High ammonia levels or abnormal pH (ideal range: 6.5–7.2) can make bettas uncomfortable. Replace 1/3 of the water weekly, add almond leaves to regulate water quality, and install a filtration pump.
Deteriorating water quality (e.g., accumulated leftover food) may cause enteritis or parasitic infections. Clean the tank promptly and provide treatment.
Food-Related Issues
Dislike of feed: Bettas prefer live food (such as bloodworms and brine shrimp). A long-term monotonous diet may reduce their appetite, so try switching to different foods.
Overfeeding: Leftover food pollutes the water. Control portions to ensure they finish eating within 2 minutes, and set one "fasting day" per week to aid digestion.
Health Factors
Parasitic or bacterial infections: Conditions like ich or enteritis are often accompanied by physical abnormalities (e.g., lesions) or unusual swimming behavior. Isolate the sick fish, treat with yellow powder or coarse salt, and temporarily.
Chronic enteritis: Symptoms include weight loss and abnormal feces. Stop feeding for 2–3 days and add vitamins to the water.
Other Considerations
Stress from tank mates: Bettas are best kept alone; mixing them with other fish may cause stress and loss of appetite.
Short-term hunger: Adult bettas are resilient to hunger and can typically survive 10–15 days without food, but prolonged starvation will weaken their immune system.
If your betta still refuses to eat after adjusting its environment and diet, observe for additional symptoms (e.g., white spots on the body, fin rot) and provide targeted treatment promptly.