Hi, my oranda has a white cottony tuft of growth on his head, coming from the folds in the wren. This appeared overnight as a lump above his eye and the white tuft protruding out of it. The tuft grows incredibly fast - about 1/2 inch in 12 hours. It broke off and now has regrown again since yesterday. My first thought was a tumour, but then seeing the tuft growing, I think it may be a fungus.
The oranda, Fred, seems to be just as happy as ever. He eats and swims normally. Has anyone seen this before, and how should I treat it? If a fungus, should I treat the entire tank or isolate Fred in a quarantine treatment? My other goldies (not orandas) are unaffected.
Water quality - nitrates and nitrites were slightly elevated, but not in danger range. Ph is around 7.6. Water temp is near 80F, as it's summer in Texas. I'm doing a 40% water change today by vacuum. I usually do a 20-30% change every 2 weeks.
I have added a live plant (amazon sword) for the first time about 2 weeks ago, and added a log ornament last week. The tank (55 gallon) and 5 fancy goldfish are about 8-9 months old.
Here's some pictures of the tuft:
First noticed it in the morning yesterday:

Second regrowth of tuft this morning:

Any ideas what to do? Thanks!!
The oranda, Fred, seems to be just as happy as ever. He eats and swims normally. Has anyone seen this before, and how should I treat it? If a fungus, should I treat the entire tank or isolate Fred in a quarantine treatment? My other goldies (not orandas) are unaffected.
Water quality - nitrates and nitrites were slightly elevated, but not in danger range. Ph is around 7.6. Water temp is near 80F, as it's summer in Texas. I'm doing a 40% water change today by vacuum. I usually do a 20-30% change every 2 weeks.
I have added a live plant (amazon sword) for the first time about 2 weeks ago, and added a log ornament last week. The tank (55 gallon) and 5 fancy goldfish are about 8-9 months old.
Here's some pictures of the tuft:
First noticed it in the morning yesterday:

Second regrowth of tuft this morning:

Any ideas what to do? Thanks!!