I posted in the cichlid forum but only got one response to remove the serpae tetra, which I did. I did this almost a week ago, but I have not seen any improvement. Here is the problem I have:
The top fin is white and kind of shredded looking, but I have noticed that on the part where the body meets the tail there is one white little bump on him. I was wondering if anyone had any idea what is wrong with him or could be wrong with him and what I should do.

The top fin is white and kind of shredded looking, but I have noticed that on the part where the body meets the tail there is one white little bump on him. I was wondering if anyone had any idea what is wrong with him or could be wrong with him and what I should do.