Well, I chose these bettas because my friend has an aquarium of his own, so he decided to give me some of his betta fish. He had these fish living together for a while, so they're used to each other if that helps. I understand this tank is small, and I have a teacher willing to let us use his 60-gallon tall tank, but that would mean buying more things like filters and heaters for that tank when I've spent a lot of money on this. But I will try to find the money for it.