With their long delicate fins, betta fish need a tank with low water flow and lots of places to hang out and nap. A 5-gallon tank is ideal for most betta fish, and they should never share their ...

You should never keep a betta fish in a tank any smaller than 5 gallons, but larger is better. Something between 15-20 gallons is ideal for a betta fish and a handful of suitable tankmates.