Bart the oranda

Question
After my young Oranda Bart having fin rot. I bought some medication from the local pet shop. The medication was by interpet. I put the required dose into the tank and now his fins and body where he was unwell have turned black. He is eating and although not as lively as he was he is swimming about. But he has not been mixing with the other two Orandas and just sits facing a plant in the corner unless it is feeding time. Could this black marks be the medication or has the disease got worse I feel so sorry for him as he is not a happy little boy. I still think he is quite strong though.

Answer
I would hope this would not be from the medication but it may be if it is a bad brand or out of date. Is he in a hospital tank or in with the normal fish tank? It would be best if he was in a hospital tank, but its ok if he is not if you do not have one. I would think you should get a new treatment, even though I do not know for sure if thats what it is, it would be a good idea to just be safe. Get one that covers the fin rot and fungus, try it. Make sure you do water changes as well, according to the directions. The only thing I can think it could be other than the treatment would be a more advanced disease, perhaps a fungus or even the fin rot. Get the new treatment and try that and let me know. I hope he gets better, its never a good thing to see fish in distress. Let me know any more question you may have. I am sorry I could not give definate answers, you can always ask more experts to make sure there is not something I am missing or have forgotten about.
                                        Rachel A.