Setting Up a Betta Fish Community Tank
The first thing to consider when establishing an aquarium that a betta will share with other fish and animals is the size. The rule of thumb is to have a gallon per inch of fish – so a school of danios or tetras might require more tank than the beginner bargained for. A snail or frog might be a better choice for tanks under 5 gallons.
Next, make sure that there is aquarium decor – such as plants, driftwood, rocks or caves – that give the betta (or its tank mates!) a place to hide in case someone gets "nippy."
It’s important to proceed with caution and monitor the betta and its new tankmates as they grow accustomed to each other, but in a big enough aquarium, bettas can peacefully coexist with other animals.