Cory issue maybe

[starsman20]

Just noticed this tonight. A little light spot above the fin. It isn't acting ill and this may have always been and I just didn't notice. Thoughts?

[Ken Dyer]

I would make sure I keep the water clean and observe for any changes. If it gets worse water changes and or a little salt would be where I would start out. But if no negative change then good food and clean water as normal 🙂

[Joshua14]

Welp I'm two days behind on this post. But I was getting ready to move some bronze Corydoras yesterday and noticed the same thing on one of them right above the fin. 

I decided not to move them and did a significant water change and cleaned everything very well. 

Today he looks a tad bit better. I'll do another small water change and continue to monitor it. The other two cats he is with seem absolutely fine and healthy, and so does he besides the mass attached to him. 

[Kaste]

On 11-6 received my shipment of fish, 6 Panda corys includes, Along with tetras. 

Treated QT tank on 11-6 with trio for QT.

11-16 used Paracleanse,

11-20 noticed what look liked cotton on cory fin, researched and discovered, its a fungus

11-20 water change, clean, and treated tank with Maracel & Ichx. 

11-23 - As of today, no other fish with fungus, but I can still see it on the Cory, not sure what to do next, wait till Friday (my usual tank clean/water change day or do another treatment.  

Any advise would be appreciated.  I am new to this, learning and making lots of mistakes 😒

[starsman20]

Update. This morning he seemed fine. 0 ammonia 0 Nitrite. <5 nitrate but when I came home he was dead on the bottom. None of my other fish in the tank show this. 1 powder blue dwarf gourami 10 neon tetra now 4 juli corries and 3 siamese algae eaters plus 2 nerites. I am sad.

[Ali]

@starsman20 I've lost several Julii cories due to what I think is the phosphate in my tap water. I lost one by one until my school was gone. I tried again with fish from a different store, and I again lost them all slowly one by one. I only have one female left, and she's going strong!

Phosphate is the only culprit I could figure out. I never thought to test it since people say it corresponds to the nitrogen levels. I bought a phosphate kit and found that my tap water is absolutely fine, except for phosphate! I know some fish are pretty sensitive to it, so now I have to chemically filter out all of the phosphate. All my tanks are doing great now. I haven't had a mass loss since. 

[starsman20]

CrapI hope its not phosphate because i was having some plant issues and o e suggestion was to use flourish advance, which adds phosphates.

[Kaste]

I lost my battle with my Panda Cory, finally able to remove him from group tank yesterday and put him in isolation.  This AM he was like a fuzz ball, dead.  I still have 4 Panda, 4 Pygmy and 9 very small Harlequin Rasbora in the 55 community tank he came out of.  No other sick fish. 

I had treated yesterday with Maracel and Ickx (whole tank).  

Do I clean the whole tank? Large water change?     Thanks,