 Listless/Dying Rainbow Shark?
Not entirely sure what is going on here. The past few days my rainbow shark has been hiding more than usual, but I recently rearranged the tank so I thought that may have had something to do with it. Today he is beside the driftwood laying on his side. After he "falls over" he wiggles to get himself back up straight, then continues in this loop. My female swordtail is also being sluggish but she is old, and may be also be ready to pop. I am very concerned about my shark. At first I thought it must have been a water quality issue, so I did a test, ammonia/nitrites are both zero, and nitrates are 5. I did a large water change a few days ago when I rearranged (about 50%) but every couple months I always do a large water change. There's no one to pick on him, he's the biggest in the tank. Tank is also only lightly stocked. Only about 20 or so inches of fish in a 55 gallon. He doesn't look overly pale, I have seen him pale in the past while under stress and his color seems normal. All other fish seem fine. He's usually a very skittish fish, but my kuhli loaches have been running over him all morning and he's not budging. Anyone have any ideas whats up? | 
