Sick Fancy Goldfish

Question
Hi,
I have recently moved my fancy goldfish from a 3 gallon tank to a 10 gallon tank.  I perform regular weekly water changes of 2 gallons, being sure to check temperature, and add cycle to the new water.  We added 3 new fish to the tank, and about a week later one of my 2 original fish got sick.  He sits for a long time at the top of the tank, fin clamping, and grayish white patches on his body and tail.  These patches seemed to be fungal so I have treated the tank (3 days) but no improvement.  I have also noticed two of the other fish nibbling at him, although there is no physical damage evident from this. All the other fish seem perfectly healthy.  Any ideas what may be making him sick?

Thanks.

Answer
Hello,

Based on these symptoms I believe your fish had 'body fungus' which is not a true fungus at all. This could be why the fungal medicines are not helping. There is a product called Maracyn which should prove much more effective.

I hope this helps.

Regards,
Stephanie