Tap water is usable for keeping betta fish, but it must undergo appropriate treatment—otherwise, it may pose risks to the fish’s health. Below are specific precautions and treatment methods:
1. Chlorine Removal from Tap Water Is Mandatory
Tap water contains chlorine, which can damage bettas’ gills and the mucous membrane on their bodies, leading to difficulty breathing and weakened immunity. Common treatment methods include:
Sun Exposure Method: Let the tap water sit still for 1 to 5 days to allow chlorine to evaporate naturally.
Water Conditioner: If time is limited, add a chlorine remover (water conditioner) to treat the water quickly.
2. Requirements for Water Temperature and Quality
Water Temperature: Adjust it to 24–28°C (Chinese bettas are more cold-tolerant and can withstand lower temperatures). Avoid large temperature fluctuations, as sudden changes stress the fish.
pH Level: Neutral to slightly acidic water (pH 6.5–7.2) is recommended. The dissolved oxygen level should be at least 5mg/L to meet the bettas’ respiratory needs.
Water Change Frequency: Replace 1/3 of the tank water weekly. This helps maintain stable water quality and prevents the buildup of harmful substances like ammonia.
3. Other Precautions
Tank Selection: Avoid round fish tanks, as they can easily cause stress to bettas (the curved glass distorts their vision, making them feel insecure). A tank with a capacity of 5 liters or more is recommended to provide sufficient living space.
Alternative Water Sources: If conditions permit, unpolluted river water or lake water can be used. However, always test and ensure its safety (e.g., check for harmful bacteria or chemicals) before adding it to the tank.
4. Controversial Opinions
A small number of opinions claim that bettas have strong vitality and can be kept in direct tap water without treatment. However, most authoritative sources emphasize the necessity of water treatment. For the sake of the fish’s health, it is advisable to prioritize safe treatment methods.
In northern regions of China (such as Hebei Province and Beijing), tap water tends to be more alkaline. For long-term betta keeping in these areas, using purified water or filtered water is recommended to adjust the water’s pH to a suitable range.