Is your betta also in a sorority? The small pink betta is the most aggressive in mine even though she's the smallest. Although, the red one is still the top dog despite being more calm as long as others don't mess with her
Thanks. The tank is 25 liter or about 7 gallon. It's too small for the amount of fish but I'm too broke to afford bigger tank. If you use a small tank like mine, it requires a bit more care and attention. Anyway, you should try, have fun and maybe post a video about your experience
In short, buy female bettas that have been bred and grown in a community, the younger the better. When choosing the bettas, pay close attention to their behavior. The milder your bettas' temperament the better chance they live well in a community with other bettas. Regardless, luck still plays a big role. Some bettas are never meant to live with others.
In the video series, you can see that I started with 9 bettas but eventually, only 5 made it. The others were just too aggressive, so they were released into my friend's pond. It's big enough that they don't really have to coexist because they rarely see each other.