I was gone for 4 days on vacay and when I returned, I found my dwarf gourami laying on the ground side ways. Whenever I get close to him, he moves a little bit, but he is definetaly sick. He just lays down side ways breathing. I check my water, and it tested: 0 amm, 0 nitrites, around 10 nitrate and so on. What can I do to save him?