Regarding the issue of betta fish not eating, comprehensive information from multiple sources indicates the possible causes and solutions as follows:
I. Environmental Adaptation Issues
- Stress in New Fish: Newly purchased betta fish may refuse to eat due to transportation fatigue or sudden environmental changes. They typically need a 3–7-day adaptation period. During this time, minimize disturbances and keep the environment dark and quiet.
- Inappropriate Water Temperature: Bettas are tropical fish, requiring water temperature to stay stable at 24–28°C. Temperatures below 20°C can cause loss of appetite, and below 15°C may be fatal. It is recommended to use a heater to maintain a constant temperature.
- Abnormal Water Quality: Excessive ammonia/nitrogen levels or pH fluctuations (ideal range 6.5–7.2) can lead to loss of appetite. Replace 1/3 of the water weekly using tap water that has been exposed to sunlight, and test water quality parameters.
II. Feeding and Diet Issues
- Improper Feed Selection: Bettas may be uninterested in specific feeds. Try switching to live bait (such as brine shrimp, bloodworms) or high-quality artificial feeds, transitioning gradually.
- Incorrect Feeding Methods:
- For new fish, fast them for 1–2 days initially, then feed small amounts of live bait to stimulate appetite.
- If they refuse to eat, promptly remove leftover feed to prevent water contamination.
III. Health Checks
- Disease Symptoms: Check for white spot disease, enteritis (white feces, abdominal bloating), or parasitic infections (swollen gills). Isolate and treat them, such as with metronidazole bath or yellow powder disinfection.
- Stress-Induced Cold: Sudden water temperature changes exceeding 3°C can cause cold-like symptoms, such as fin clamping and bottom dwelling. Gradually raise the temperature (≤3°C per day) and stop feeding.
IV. Additional Considerations
- Environmental Setup: Provide hiding spots like aquatic plants and driftwood to reduce stress.
- Seasonal Adjustments: Strengthen insulation in winter and avoid direct sunlight in summer to prevent overheating.
If the betta still refuses to eat after these adjustments, it is recommended to further diagnose the cause by combining water quality testing and physical examination of the fish.