Open Sores/ulcers

[stonecoloured]

Good afternoon,

I've been a long time lurker, and fish keeper... I hope some of you can help.

I have had something running the course of my 900l tank.

As it was, initially, contained to the rainbows I 1st thought it was just ulcers showing they were eating too meat-rich a diet.

Until it started going through my Congo Tetras and Cory cats.

I've treated for bacteria, and previously treated for fungus (for another problem) - so all I'm left with is parasite or viral.

Please find the symptoms below :

Open raises sores that are red, ruffle the scales and looks angry. In some cases it has white tinges, however I think this is due to dead scales/flesh rather than a symptom.
The sores start mainly around the head or belly area and then spread throughout the body in patches/streaks.

Please can someone give me some ideas what I'm facing. Infected fish can live for Months on end... and then one day start gasping at the surface of the tank and die.

I’m getting a microscope to try and get a slime sample... although TBH I don’t know what I'm looking for (as I've never done it) so any help there would be of use also.

Thank you for taking the time to read this.

Stonecoloured.

 

[WILDER]

How many fish and which type.
Water stats in ammonia, nitrite, nitrate, and ph.

Is there white edging around the sores, or a white centre to the sores.
Is the skin peeling or shedding.
What the name of the bacteria med you have used.

Any signs of flicking and rubbing, or excess mucas.