I noticed that my platy has started sitting on the bottom of the tank lately. Well just a few minutes ago I found him laying on his side behind a piece of driftwood in my tank. I tested the water and Ammonia, Nitrates, and Nitrites are all 0. pH is around 7.0-7.5. That's the only thing that seems wierd to me. Temperature stays at about 80-83. He seems like he is having a little trouble swimming corretly, the back of him kinda droops down when he swims. He isn't eating flake food, and I tried some sinking food right around where he is and he doesn't go for that either. Any help would be appreciated!! I don't want to lose him.