Ok, a fight has broken out between literally every fish. Yesterday, I witnessed the largest Tetra bop Sparky in the head. He went all around the tank, and broke the group. The small tetra bumped into the largest. All the tetras now pick on him. Sparky made a lair under the sponge filter, and has been hiding ever since, only coming out for food. He also broke one of his top fin bones. This happened about a week ago, when he tried to wedge himself into the corner by the sponge filter. It was like you trying to cram yourself into a wall half the size of yourself from the top. He got freaked out, and his fins went up. Broke 2 or 3. Will never look the same, but he is swimming fine. I think I need to get a few more Tetras for the group, to spread aggression. The smallest one is looking so pathetic. Do you think they could go outside in the patio pond?