Rednekgrl82
Aquarium Advice Newbie
Hello, I have had fish off and on my whole life, but mainly goldfish or guppies. About 6 months ago I inherited fish from my brother when he moved and he decided not to take the fish with them. He gave me 2 glofish tetras, a purple one and an orange one. He had 3 but the purple one killed the pink one which was smaller. He had the 3 in a 10g tank. When I got the remaining 2, I put them in a 20g tank. I really wanted to have more than 2 fish. I started some research and one pet store said that they are schooling fish and that it was stressful to have less than 4 in a school. I waited about 2 months before I bought a new blue glofish tetra. They all have adjusted very well. They seem very happy with each other. And then 2 weeks ago I bought a red glofish tetra. Now my orange one is bullying the purple one. Did I do something wrong or is it normal for one to just change it's behavior so sudden?