Whitish Fluff Has Turned Red?!?

[abe]

I noticed that my new peacock had a fluffy white patch on his side, so I did a water change. It didn't get any better after a few days, so I tried to catch him, with no luck... I finally did catch him tonight, probably because he's a bit worse off. He is now in a clean hospital tank.

So, what is this? I thought it was just fungus at first, but now the worse side has turned a red/pink/rust color. What should I treat him with?

And is "instant ocean" salt the same as aquarium salt?

 

[LauraFrog]

This looks bacterial to me, probably a strain of columnaris similar to the one I had last year. Mine looked virtually exactly like that and went through all my bettas - but I had an 18 hour kill strain - fish dead 18 hours after exposure. Yours looks to be progressing a lot slower, so you have a chance of saving him.

The difference between the various aquarium salts/marine salts etc is that some of them are only (or mainly) sodium chloride (which is table salt without the additives). The true 'marine salts' and some of the others contain other salts (magnesium, sodium, carbon and calcium compounds mostly) that increase the water hardness as well as the salinity.

It's the sodium chloride that could be useful here - use it at 2-3 tsp/gal until you can get some antibiotics, which are likely to cure the problem. Any antibiotics pretty much should knock columnaris - tetracycline, Maracyn 1 + 2, kanamycin/streptomycin/erythromycin... all aquarium antibiotics are broad spectrum and they should all work, if you can get them onto him pretty fast.

There's a chance it could be fungal, but my money is definitely on bacterial.

 

[Amerce]

Quick word of advise all equipment and tank you have used will need to be sterilised if it is bacterial to avoid spreading it throughout your other tanks.

How long have you had the fish in your general tank, watch out for it on the other fish.

 

[LauraFrog]

^ Absolutely, columnaris is FOUL for doing this, and most bacterial illnesses will. Do not use the same nets/food/anything from the tank the infected fish was in and any of the other tanks. This is how I spread it around mine - I lost over half of my bettas, and in the end I had to euthanise every fish that had been exposed because I couldn't stand to watch them all dying, one by one.

If none of the other fish are showing symptoms you probably won't get a tank kill, but adding a gentle antibacterial (melafix is perfect) might be a sensible precaution.