Originally Posted by KoPi
My (little) sister is 11 years old. Do you buy the pellets and frozen worms separately? My sister is currently feeding him bettamin flakes. Is this okay? I don't believe she cleans the water either... Is a filter needed as well? Sorry, I only raised hamsters in my life :/
In a 1 gallon bowl a filter will only create a current that is unwanted by bettas. Consistent water changes will work just as well and allow you to keep your current set up without fiddling too much. At the very least the addition of a thermometer (a glass one that hangs inside the tank is most accurate) will let you see if the temperature of the water is suitable for the fish.
A lot of people don't suggest flakes for bettas as they can be easily overfed and can lead to bloating. The best quality pellets are Omega betta buffet, or New life spectrum. You can safely feed him 4 - 5 a day.
The worms referred to in a different post can refer to a variety of frozen treats people like to feed their betta. Bloodworms are common, but they'll also accept a variety of frozen treats, but treats are exactly what they are. The majority of his dietary needs will be met by the pellets, the frozen foods are more of an occasional dessert.
I'd say the most important step would be seeing if you can take over the primary care of the fish. Proper food and water changes will keep a betta healthy, but constantly being touched and chased will stress him out, and a stressed fish is prone to diseases that can and will kill him. If your little sister does not yet fully understand, it is very important that someone explains to her that betta fish can not live with other bettas. Maybe have the pet store person explain it to her when you're picking up fish supplies or something.