Dividing a Betta's Tank

Bettas are a type of fish known for being particularly aggressive towards each other, making it impossible to keep more than one in a fish tank. If you have more than one betta, divide the tank so they can not attack each other.

  1. The Set-Up

    • A divided tank is a regular tank with clear partitions made of either glass or plastic. Most partitions available on the market are made of glass. These don't allow water to circulate as well as partitions made of plastic. The partitions should have gaps large enough to allow water to flow through but small enough that the Bettas can't slip through. A divided tank also needs a filter that's strong enough to move the water throughout the tank. Under-gravel filtering systems are recommended.

    Pros

    • Divided tanks let you house several male and female Bettas in the same tank without worrying about fights. And since you're keeping your Bettas in a tank with a filter system and not in individual bowls, you don't need to worry about regular water changes. Divided tanks also let you keep multiple fish with less maintenance.

    Cons

    • The divided tank setup has two disadvantages. First, it enables the spread of disease among your Bettas. Water is a great medium for bacteria, so if one Betta gets sick, they all get sick since they're sharing the same water.
      Second, spawning Bettas in a divided tank isn't practical since the young Bettas are small enough to swim through the gaps in the dividers and will be eaten by the other Bettas as soon as they do. In addition, young fish can get sucked into the filter and killed. Spawning tanks also need a heater so they can be kept at 80 degrees, which is too warm for adult Betta fish.

    Considerations

    • The divided tank setup is great if you're interested in housing several adult Bettas and can quarantine any new Bettas before putting them into the tank. This will greatly reduce any chance of spreading disease. If you plan on breeding your Bettas, make sure you have a separate spawning tank set up. And take care when choosing a filter for your divided tank. If you have anything other than an under-gravel filter, the Betta nearest the filter will have the cleanest water in the tank but is likely to experience the most turbulence. Keep in mind that Bettas prefer calm water.