Oscar lethargic, not eating, slightly bloated. Need help diagnosing and treating

Maxdevine00

Black Skirt Tetra
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Jul 29, 2020
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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?
21-30%
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.
I have a ~10 inch Oscar (6yrs old) that has been in excellent health forever. Over the past few weeks he has gradually become more lethargic and in the past week he has stopped eating any food and barely moves. I do weekly water changes of ~25% and have not changed anything in the aquarium. He is not lying completely sideways and is able to swim slowly. He might have slight bloating but hard to tell for sure. He is in a 75 gal without other fish. Tested water and ammonia is 0, nitrite is 0, nitrate is ~20. Temp is 78f. Not sure if this is constipation, infection, tumor, eggs etc but I want to get a handle on this asap. I have been using seachem stress guard, stability, and cichlid trace elements. Not sure if he will eat a pea due to appetite. I don’t have a “hospital tank” and was hoping to avoid that stress on him/ me as he hates being netted and it makes a huge splashing mess. Also not sure antibiotics would be risky and harm bio filter media. Any help would be appreciated!
 

kno4te

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I’d dose some epsom salt 3-5 tbsp per g to the tank. Dose some fritz metrocleanse to the tank. If the fish has an appetite then mix metronidazole in food and feed to the fish till swelling improves.
 
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Maxdevine00

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I’d dose some epsom salt 3-5 tbsp per g to the tank. Dose some fritz metrocleanse to the tank. If the fish has an appetite then mix metronidazole in food and feed to the fish till swelling improves.
Thanks for the advice! I’ll dose epsom salt today but have to wait for metrocleanse to arrive. Also, after dosing the epsom salt how soon should I do a water change?
 
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esoxlucius

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If your oscar makes a full recovery from whatever this is, moving forward I'd increase your water change volume too.

Although you state that your nitrate is 20, which is at the top end of acceptability really, 25% per week is a bit on the wimpy side. It would help your oscar no end if you could keep your water a lot "fresher" that than.

I wish you the best of luck.
 
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kno4te

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Thanks for the advice! I’ll dose epsom salt today but have to wait for metrocleanse to arrive. Also, after dosing the epsom salt how soon should I do a water change?
I’d do a large water change prior adding salt and meds. Want to keep the same concern of epsom salt and meds at all times while treating.
 
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Maxdevine00

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Thanks for recommendations on increasing water changes. Not much change after 1 day of epsom salt (1tsp/10gal). Also started seachem paraguard yesterday while other meds ship. Any ideas on what is most likely diagnosis?
 

FINWIN

Alligator Gar
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Dec 21, 2018
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I don't want to assume anything here but

It could be a chronic condition developing over time (slow nitrate poisoning). If he's been in a 75 alone for 6 years with only small water changes is not nearly enough and will def cause issues. Oscars make massive waste both the kind you see and don't see.

You mentioned at 6 years your O is just under 10 inches....that's small for an adult O. It could be an indicator of not enough clean water over time. Can you post up a pic?
 

Maxdevine00

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Jul 29, 2020
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No acute worsening but he is also not much improved. Have been doing 25% water changes every other day, adding stress guard, paraguard, stability, epsom salt. I noticed bilateral eyes have faint hazy spot that almost appears like an irregular shaped contact lense. They are very subtle and not whited out or bulging like other pics online. Was curious if this piece of info changes treatment.
 
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