Whether betta fish need a heater depends on their specific species and breeding environment. Below is a key analysis:
I. Heating Needs Determined by Species Differences
Siamese Fighting Fish
Heating Required: As tropical fish, they need a stable water temperature of 24-28°C (optimum 26-28°C). Temperatures below 20°C make them prone to illness, and prolonged exposure to temperatures below 15°C can be fatal.
Winter Essential: In northern regions or environments with a daily temperature fluctuation exceeding 3°C, a heater is necessary. It is recommended to choose a device with temperature control (e.g., 50W for a 30-liter tank).
Chinese Bettas
Natural Winter Survival: These are eurythermal fish that can tolerate water temperatures between 4-31°C, but their optimal growth temperature is 24-28°C.
Recommended Heating Scenarios:
When water temperature is consistently below 10°C or daily fluctuations exceed 5°C;
A constant temperature of 26°C is needed during the breeding period to improve hatching rates.
II. Impact of Seasons and Regions
Winter: Heaters are required in unheated northern regions (Chinese bettas need ≥22°C, while Siamese fighting fish must have ≥24°C).
Spring & Autumn: When daily temperature fluctuations are large, Chinese bettas need a heater to stabilize water temperature (e.g., set to 24°C).
Summer: Heating is usually unnecessary, but measures to prevent overheating are needed (use a fan or ice pack if temperatures exceed 30°C).
III. Recommendations for Using Heating Equipment
Power Selection: Use 50-100W heaters for small tanks (under 30 liters); for larger tanks, calculate based on 1-2W per liter of water.
Placement Tips: Position the heater diagonally near the filter’s water flow to avoid local overheating.
Temperature Fluctuation Control: When changing water, the temperature difference between new and old water should be less than 2°C, and the temperature should not rise more than 2°C per hour.
Conclusion
Siamese fighting fish must be heated, while Chinese bettas require heating based on environmental conditions. Heaters can significantly improve the health of bettas and breeding success rates, especially for temperature-sensitive species and during periods of seasonal change.