Single Large White Spot on Cory

[Alshain]

I have a green cory in my tank who has grown a single large white cyst like spot from the back of his dorsal fin. I noticed it while doing a water change this evening. It doesn't really look like Ich but I'm not certain. Its only one spot and its very large, almost the size of half a grain of white rice. I can't tell if it is a cottony growth or not. Any ideas??

All tank parameters are normal, I've added nothing new in the last several months. No other fish seem affected by any noticable symptoms. Its a 55 gallon tank fully stocked.

1~Green Cory
2~
Ammonia 0ppm
Nitrite 0ppm
Nitrate ~40ppm
PH ~7.0
3~ 55g, almost a year since I set it up, been running with no diseases or problems for at least 6 months.
4~Rena XP2
5~10 Swordtails, full grown. Lots of fry.
1 Young (3 inch) Clown Loach
4 Cories
Unknown number of Otos (little buggers hide, I don't know how many have survived but at least 2, started with 7)
6~Today, before that 1 1/2 week ago. 25% water changes
7,8~Nothing new added in several months.
9~Mixture of Omega veggie flakes and Omega shrimp pellets.

 

[Jchillin]

Can you post a pic of it?

 

[Alshain]

Best I can do, my fish dislike cameras. Right now I'm operating under the assumption that its a fungus and treating with Pimafix. No other white spots have appeared anywhere on any of the fish.

 

[Sitchy]

I had something that sounds similar to this on one of my Guppies and i treated it with a fungus, finrot and bacteria treatment and it cleared up in about a week it got worse before it got better though. The spot on my guppy was raised but you could only see it from an angle and it affected one of its pectoral fins.

Cant be sure its the same thing though.

 

[Alshain]

Sounds kinda like this. Visually you can kinda see it from both sides, but while taking pictures I could only see it from one side. I guess I will stick with the Pimafix then.

 

[squeekness]

Use Malafix with the Pimafin. They are made by the same people and sorta work better together. You have a large tank so buy the pond strength if you can find it. It's a bit more money but stronger.

 

[ladycage]

If it is columaris use Melafix and Pimafix and it should clear up, I had a molly with a big white cotton patch but melafix and pimafix and healing it.