please help my congo tetra

[xxdiamonddebxx]

My congo tetra stopped swimming yesterday and i move him to my empty tank in the bedroom. When i put him in the new tank he just sunk to the bottom. Today he has showed some progress and has been moving round the bottom of the tank, he is still eating although i have to put it right infront of him. I can see his fins all work he has no markings or any visible signs of any other diease but his tail doesnt work it just twitched once in a while is there anything i can do to make him better. Please help

 

[Lateral Line]

Was the Congo behaving normally before and suddenly stopped, or is it a new fish? What else is in the tank he was in and are they behaving normally? Did you do anything just before the problem started, water change, new fish, etc...?

 

[xxdiamonddebxx]

the water is fine ive tested it and all my other fish are fine i even tested the water in my tank upstairs before putting him in there he is still eating and all he does is flip around the bottom of the tank its as if his tail doesnt work properly and just twitches one way and wont bend the other way. The last water chang i did was two weeks ago and its all the same fish. I only have 6 neons, 4 congo tetras and a alge eater in a 3ft tank at the moment not as if theres too many fish either.