I noticed today that my goldfish, Thunderbolt, has a tuft of white on its head.
Note: Same fish. coloration difference due to camera flash
I've had the fish in a 10 gallon tank by itself for about 3 years, and I have not recently changed anything. The only minor change I can think of is adding an old algecide tablet to the water about 6 weeks ago, but this growth is much newer than that.The water is also slightly cooler now that winter temperatures have arrived (the tank is about 68oF vs 78oF a few months ago -- but this has been a gradual decline and not unusual for this time of year). I last did a 30% water change about 2.5 weeks ago.
Any idea what this might be and what I can do about it?
I don't want to lose my fish :(
UPDATE:
I initially gave my goldfish a salt treatment (~1.5tbsp of aquarium salt / gallon), which caused the white tuft to rescind to being only a white spot (no fluffy outgrowths). I thought my fish was on the way to recovery.
However, about 2 weeks later (~1 month after initial symptoms), my fish's condition worsened. The fish lost almost all control of its air bladder (which I began treating with peas, which helped) and became very lethargic. On a few occasions I've found the fish resting motionless being partially sucked up by my filter. The white tuft had likewise started growing again...
I started treating my tank with API Fungus Cure (contains Victoria Green B + Acriflavine).
I'm on day 4 of treatment, but now my fish looks like this:
The spot has grown lumpy and red/bloody... (does this suggest a secondary bacterial infection perhaps?)
Now what should I do??....
UPDATE2:
It's been 6 months, and my poor little goldfish has been a real trooper. I treated the water on 2 additional occasions with the API Fungus Cure (which totaled 3 complete treatments in ~3 months). The spot remained red and tufty for more than a month. However, after all treatments (and time), the spot is certainly no longer tufty or red and has not been for at least ~3 months now. Instead, it's just a white looking scab on his head. I ASSUME THIS IS GOOD?
However, his behavior has never been the same :(.
Specifically, his air bladder control seems to be near non-existent now, and I find him stuck upside down about 80% of the time.
Though, actually it's better than it was 2-3 mo ago -- he would purposefully wedge himself between plants or rock to keep himself from floating to the top. Now he seems to have a bit better control.
feeding him peas 1-3x per week momentarily helps him a bit, but not as much as it used to when this ordeal first started.
One other thing to note: the tank randomly turned very cloudy and stayed that way for a month starting about 6 weeks ago. This was more than a month after my last fungus treatment. Water changes did nothing, but finally I came home one day and the water was clear again. The fish never seemed bothered by it. I assumed it was a bacterial bloom, but in a 10 year old tank seemed strange... (I'll have to ask a new question about this one).