http://forum.aqua-fish.net/ A forum devoted to aquarium fish, plants, techniques and fish keeping as a whole. en http://forum.aqua-fish.net/?topic=new-betta-females-in-my-tank#1 Hi guys, I&#8217;ve got a problem with my new fish. I introduced 2 Betta females today to my tank which is running for 1 week only. There was 1 Betta male already. I was hoping that he&#8217;ll welcome them and that he&#8217;ll be showing his fins to both of them. Unfortunately, he started to be very aggressive . Will they be fine later? I don&#8217;t want to see my fish killing each other . Or do I have to buy another aquarium and keep them separately? Thanks!!! Susan original post: December 23, 2006, 10:58 am anonymous 2008-05-01 http://forum.aqua-fish.net/?topic=new-betta-females-in-my-tank#2 Hi, Do they have any places to hide? Bettas are very aggressive if the conditions aren&#8217;t appropriate. Think about larger tank or keep them together for breeding purposes only. I successfully kept Bettas in a tank of 100 litres; 1 male and 3 females. However, this wasn&#8217;t very good, since he was apatic towards 2 of them. It&#8217;s good to keep only 1 male and 1 female. 50 litres tank sounds like a small one. Try to use as many plants as possible, so they could hide . Peter anonymous 2008-05-01 http://forum.aqua-fish.net/?topic=new-betta-females-in-my-tank#3 Unfortunately, male bettas are very aggressive toward and may even kill a female unless she is spawning. I would advise instantly isolating the male to prevent further damage and thinking about purchasing an extra tank. BettaLove<3 2013-01-15