My water is good. This neon tetra was first looking a little bloated last Friday so I gave him a boiled pea. He got a little bit of it. Since there he's been looking more shiny than normal and he can't swim straight. He keeps turning to the side and falls when he goes very high. He spins in circles, gasps, and flops his tail continuously. He also seems to be in a bad mood, he chases away fish that get too close to him. I'm really worried.