Please help!! I have a 30gal tank that I have had for over a year. Ph 7.1, Nitrites 0, Nitrates 40, Temp 78. I have 2-Angels 4 1/2", 2-Figure 8 Puffer 2", 1-Pleco, 1-Cory. Over the last month my female angel has been bitting the male. She has ripped off his lips and part of his forehead. He is fine just funny looking. The female has been looking no so good over the past week. She is staying at the bottom on her side or upright. When I or one of the other Fish touch her she will swim off and hide somewhere else. At times she looks ok and at times she looks like she is dead. She does not look discolored,stressed, or sick just not active. Before she began this action she kept wedging herself between the glass and the heater. Any help will be thanked.