I'm trying to identify and treat an illness that many of my fish have died of.
Symptoms seem to be internal, and appear like swim bladder issues, but often the fish have sores on their sides. I've found dead fish that I hadn't noticed being ill, and any fish I've seen with symptoms has died within a few hours or half a day. I've seen one harlequin rasbora with something hanging out of it instead of poop (check photo)
I had a number of explained deaths over the months and have lost rubbernose pleco, gouramis, corys, and others. Recently, fish I've have seen with clear signs of disease have been dwarf gourami and harlequin rasbora. So far I've lost about half my fish over the last few months.
My tank is 160l
Ammonia 0 ppm
Nitrites 0 ppm
Nitraties 5 - 10 ppm
Currently have bristlenose pleco, harlequin rasbora, otos, khuli loaches, corys in my main tank (and a dwarf gourami who is in a quarantine tank).
I've tried to treat with bacterial and fungal, parasite treatment and aquarium salts.
I thought it might be columnaris, but i don't know..