Question: What size fish tank should I buy for my Betta fish?

  Options: 
 A. You can buy a tank as small as the Betta is. The fish will acclimate to its surroundings. It won't grow much in a small tank, but it will adjust.
 B. The smallest size a Betta should have is 2 1/2 gallons. However, try to go bigger if you can. You want your fish to have lots of room to swim and grow.
Answer: B