Oscar's chronic hole in the head

[Denis Dorokhov]

Hi there!

I have a problem with my 3 years old oscar (another oscar and the others are OK): since November 2018 he has hole in the head disease, I already treated him 2 times without much of the success. My aquarium is 500 liters, 5 fishes 25-35 cm: 2 wild oscars, 1 petenia splendida, 1 jaguar, 1 pleco. I feed with different Hikari dry foods (cichlid gold, carnivore sticks, massivore delite). But mainly he eats Hikari Cichlid Gold. Water tests do not show anything bad, zero ammonia / nitrite, 30-40 of nitrates before the water change (5-10 of nitrate is in the tap water), I do 50% water change every week. Hardware is Eheim 1200XL, Fluval FX6, 500ml of fresh activated carbon constantly in the internal filter, small UV sterilizer. Temperature is 26 celsius degrees. The aquarium is 3 years old.

The story begins in November when my oscar rejected to eat and a day after he got 2 holes on his head. I immediately got ESHA HEXAMITA from a local pet store and did 2 sessions of treatment in the common tank. The guy started eating again shortly after starting the treatment, the holes started to cure, but the progress was extremely slow. In the beginning of February he again rejected to eat with one more hole. I didn't like ESHA medicine last time, because my other fishes reacted badly on it (especially petenia). This time I tried JBL SPIROHEXOL, did 2 treatment sessions (2 weeks). This time the holes cured better, he started to eat again, I did a water change 2 weeks ago, removed the medicine with activated carbon, and after another water change last Sunday he now again rejects to eat and gets one more small hole. So my questions are:

1) Is there anything wrong with my setup? I had some minor problems before, but I could perfectly handle it, it's the first time these 3 years I really have no idea what to do, nothing helps.
2) How should I treat him now? I could try pure metronidazole, but it's extremely hard to find without a prescription (I'm in Germany), I heard it helped many people in quite serious cases. But I would prefer some easier factory type medicine.
2) Should I treat him in the common tank? From my understanding it's a good idea and those medicines against hexamita don't harm the filtration much.

Thank you very much for your recommendations.

 

[kno4te]

Metro is preferred. Still with go with it and maybe some methylene blue in the affected areas. Clean water and a good based pellet. Remove carbon and make sure no stray current in the tank. Not much else.

 

[tlindsey]

Your aquarium tbh is over stocked and the bio load is the issue. You will need to do larger water changes in the future. This will be the only way to control HITH.

 

[duanes]

To me, although meds help, they do not address the underlying problem (the cause), and unless the source of the problem is not addressed, chronic diseases just keep coming back.
IMO the 30 to 40 ppm nitrate level before a water change is problematic.
A 50% water change only once per week allows that high nitrate level to create stress and allow normally benign bacteria to become problematic, and if your water is hard and mineral rich, this adds to the ability of bacteria to infect.
Enough water changes need to be done throughout the week to keep nitrate below 20ppm.
Oscars come from natural waters which are mineral poor, soft, and where nitrate is near zero, and these waters seasonally become stained with tannins, that are also antibacterial.
My suggestion would be to forgo medication, and double or triple frequency of water changes, enough to dilute nitrate so that as soon as your test detects 20ppm you change a significant amount to bring to your tap water levels.
And if you can add tannins by soaking leaf littler in rain water, and add that tea colored water to the water change water, that may help tremendously.
This is what I had to do to keep soft water fish from becoming scarred up in my hard water. I found a 30-40% water change every other day was needed to get down to my nitrate target of 2-5ppm.

 

[HowlinMadMurdock]

Forgive me if I am overlooking something here, but isn't the carbon you mentioned essentially removing the medication from the water before it has a chance to be effective? Carbon absorbs most chemical compounds.

 

[Denis Dorokhov]

Forgive me if I am overlooking something here, but isn't the carbon you mentioned essentially removing the medication from the water before it has a chance to be effective? Carbon absorbs most chemical compounds.

The carbon was removed during the medication period of course. As well as UV.

 

[Denis Dorokhov]

Metro is preferred. Still with go with it and maybe some methylene blue in the affected areas. Clean water and a good based pellet. Remove carbon and make sure no stray current in the tank. Not much else.

Thanks for the advice! Could you clarify the dosage of metro please? I think I found a way how to get it.

 

[Denis Dorokhov]

Your aquarium tbh is over stocked and the bio load is the issue. You will need to do larger water changes in the future. This will be the only way to control HITH.

I could try doubling the WC, thanks... Anyway, I heard that everything under 40 of nitrate does not cause major problems. So probably it's because of the wild origin, could be...

 

[Denis Dorokhov]

To me, although meds help, they do not address the underlying problem (the cause), and unless the source of the problem is not addressed, chronic diseases just keep coming back.
IMO the 30 to 40 ppm nitrate level before a water change is problematic.
A 50% water change only once per week allows that high nitrate level to create stress and allow normally benign bacteria to become problematic, and if your water is hard and mineral rich, this adds to the ability of bacteria to infect.
Enough water changes need to be done throughout the week to keep nitrate below 20ppm.
Oscars come from natural waters which are mineral poor, soft, and where nitrate is near zero, and these waters seasonally become stained with tannins, that are also antibacterial.
My suggestion would be to forgo medication, and double or triple frequency of water changes, enough to dilute nitrate so that as soon as your test detects 20ppm you change a significant amount to bring to your tap water levels.
And if you can add tannins by soaking leaf littler in rain water, and add that tea colored water to the water change water, that may help tremendously.
This is what I had to do to keep soft water fish from becoming scarred up in my hard water. I found a 30-40% water change every other day was needed to get down to my nitrate target of 2-5ppm.

Thanks! Collecting rain water would be problematic for me. Could some special filter media be effective for the purpose?

 

[monkeybike]

There are studies pointing to activated carbon being a cause of head and lateral line erosion.