Hi folks, I'm looking for some opinions please.
I have a sick neon tetra. I'll give you what info I can.
I've had this particular group of neon tetras for about 6 months now.. 15 of them in total. I have them in a 47 gallon well planted tank with black phantoms, pencilfish, a dwarf gourami, kuhlis, corys, ancistrus and a couple of platys. I perform water changes each Sunday of about 30 percent, and have two internal filters running in the tank.
Last week I noticed that this particular neon had a bit of a lump on his tail, and the lower caudal region was slightly darker in colour.. almost bruised looking. I didn't think too much of it at the time, thinking that he had probably knocked himself on something. I was away for a number of days, and when I came back his caudal fin was slightly frayed looking, his eyes were slightly protruding and he was looking slightly emaciated, swimming more slowly than usual and hanging around on his own most of the time. None of his other fins appeared to be damaged in any way.
I got home from work this evening and his eyes were really bulging and he looked worse than before. Half of his caudal fin was hanging off. I have decided at this point it would be cruel to keep him in isolation while I waited to get meds - and I am about to euthanise him. I just took water readings which are:
Nitrate: 15 - 20
Another thing, on Friday I euthanised one of my corys (I've had this particular group for about three years now). I found him in the morning, he was having trouble staying upright but had no actual physical symptoms. His eyes looked clear and normal, his colouring was normal etc.
I have taken the best photos I could and hopefully that'll help in identifying what's wrong with him.