- Have you tested your water?
- Yes
- If yes, what is your ammonia?
- 0
- If yes, what is your nitrite?
- 0
- If yes, what is your nitrate?
- 20
- If I did not test my water...
- ...I recognize that I will likely be asked to do a test, and that water tests are critical for solving freshwater health problems.
- Do you do water changes?
- Yes
- What percentage of water do you change?
- 41-50%
- How frequently do you change your water?
- Every week
- If I do not change my water...
- ...I recognize that I will likely be recommended to do a water change, and water changes are critical for preventing future freshwater health problems.
Hello Monster Keepers,
I have a very serious issue and I’m hoping someone has some ideas for me.
It’s a LONG tale, I will try to be concise.
This Oscar is about 2 years old; I bought him at about 2” long and now he’s almost a foot long. Beautiful fish, excellent health, wonderful personality. Eats enthusiastically every day (until this event).
About two weeks ago his behavior changed. He was stressed, hiding, wouldn’t eat. Very unusual for him. He NEVER sulks or pouts.
In the next few days, out of nowhere, he got this huge swelling growth of the left jaw/cheek. It got so large that it was visible both inside and outside the mouth, and his mouth was stuck open. It looked awful. He also had a red open sore on his inner jawline.
Then, it “burst” for lack of a better term. There was now an open sore/wound in his mouth and lip area, and some open bloody sores on the left cheek below his eye. The eye started to bulge out as well. At this point, some tissue started to push out of his skin at the chin area. It was red and stringy; I thought it was some sort of parasite, so I treated with General Cure (which seemed to do nothing) and salt.
Over the next few days the problems swapped- the swelling went down, and his face shape went back to normal. But the sores and dead tissue got MUCH worse. Absolutely gruesome. There are strings of dead white skin hanging off his lip and mouth, inside and out. It’s awful.
This whole time I’ve been researching like crazy and consulting any experts I can find (there are no fish vets in my state). I have landed on the diagnosis of a bacterial infection; probably columnaris. So, I am treating with Kanaplex and Jungle Fungus Clear (Nitrofurazole) and an aggressive dose of aquarium salt (1 tbsp per gallon, as recommended by Aquarium Co-Op).
Yesterday I administered the second dose of those, and I do believe I have knocked out the root infection.
THE QUESTION:
What do I do about all this dead tissue on the fish? He has some white skin peeling off his mouth and lip, a very gross mass of flesh loose inside his cheek (interfering with his eating), and the outer cheek area under his eye is all puffy dead white skin, with fuzzy mold growing on it. What can I do? Anything? Let it eventually slough off?
Some notes: it’s a 90gal tank and I have been treating the entire thing. I do have a hospital tank but unfortunately it’s full of fish I am growing out.
Two tankmates: a Jack Dempsey (7”) and a Gourami (4”). Both seem fine and exhibit no symptoms. But the Jack is refusing food.
Water tests are coming back perfect. However I do wonder if I will crash the cycle with all these meds. I’ll test after water change tomorrow. PH is steady at 8. Water comes from a well and is pretty hard (KH and GH are somewhat high) so I also have an RO system and 1/3 of incoming water is RO.
Any ideas or input? Has anyone dealt with dead flesh on a live fish? Thank you all.
~JS
WARNING- this pic is awful. Not for the faint of heart.

I have a very serious issue and I’m hoping someone has some ideas for me.
It’s a LONG tale, I will try to be concise.
This Oscar is about 2 years old; I bought him at about 2” long and now he’s almost a foot long. Beautiful fish, excellent health, wonderful personality. Eats enthusiastically every day (until this event).
About two weeks ago his behavior changed. He was stressed, hiding, wouldn’t eat. Very unusual for him. He NEVER sulks or pouts.
In the next few days, out of nowhere, he got this huge swelling growth of the left jaw/cheek. It got so large that it was visible both inside and outside the mouth, and his mouth was stuck open. It looked awful. He also had a red open sore on his inner jawline.
Then, it “burst” for lack of a better term. There was now an open sore/wound in his mouth and lip area, and some open bloody sores on the left cheek below his eye. The eye started to bulge out as well. At this point, some tissue started to push out of his skin at the chin area. It was red and stringy; I thought it was some sort of parasite, so I treated with General Cure (which seemed to do nothing) and salt.
Over the next few days the problems swapped- the swelling went down, and his face shape went back to normal. But the sores and dead tissue got MUCH worse. Absolutely gruesome. There are strings of dead white skin hanging off his lip and mouth, inside and out. It’s awful.
This whole time I’ve been researching like crazy and consulting any experts I can find (there are no fish vets in my state). I have landed on the diagnosis of a bacterial infection; probably columnaris. So, I am treating with Kanaplex and Jungle Fungus Clear (Nitrofurazole) and an aggressive dose of aquarium salt (1 tbsp per gallon, as recommended by Aquarium Co-Op).
Yesterday I administered the second dose of those, and I do believe I have knocked out the root infection.
THE QUESTION:
What do I do about all this dead tissue on the fish? He has some white skin peeling off his mouth and lip, a very gross mass of flesh loose inside his cheek (interfering with his eating), and the outer cheek area under his eye is all puffy dead white skin, with fuzzy mold growing on it. What can I do? Anything? Let it eventually slough off?
Some notes: it’s a 90gal tank and I have been treating the entire thing. I do have a hospital tank but unfortunately it’s full of fish I am growing out.
Two tankmates: a Jack Dempsey (7”) and a Gourami (4”). Both seem fine and exhibit no symptoms. But the Jack is refusing food.
Water tests are coming back perfect. However I do wonder if I will crash the cycle with all these meds. I’ll test after water change tomorrow. PH is steady at 8. Water comes from a well and is pretty hard (KH and GH are somewhat high) so I also have an RO system and 1/3 of incoming water is RO.
Any ideas or input? Has anyone dealt with dead flesh on a live fish? Thank you all.
~JS
WARNING- this pic is awful. Not for the faint of heart.
