I have two betta girls. They were briefly in a 1 gallon tank together and the bigger one bullied the smaller one. She was sad and would not eat. I read a little, got the smaller one her own tank, she soon blossomed and is happy. I purchased a 5 gallon tank and am thinking about putting them in together. I have read various things and gotten varying advice. Two guys in the aquarium department at Petsmart thought they should not go in together because they will fight and one will die. Books I have read state there should be three to four in a tank together in order for there to be harmony. What is the consensus on this if there is any. I am trying to avert tragedy. If anything, I can just leave them in their little tanks (one is in a 1 gallon...I may get her a larger one) and just get different kinds of fish to put into my 5 gallon.