I need advice on what to do with my neon tetras. I currently have 10 of them in a quarentine tank as 4 of them (1 has since died) had symtoms of what I thought was Neon Tetra Disease. (Googled symptoms as have had no experience of this or any diseases).

The fish that died had a curved spine and had completely lost the red off his body. The other 3 show signs of fading red, the other 6 show no signs as yet. Currently all 9 fish are still feeding etc.

I was advised to use aqaurium salt for 3 days (day two will be today, I havent put the second dose in yet) and then on day 4, I was advised to treat with an internal bacteria treatment.

Ive since read that tetras dont tolerate salt well (hence why I have not yet put the second dose in) and now I am completely confused as to what to do.

They were all in my 120litre tank with other fish (who all seem fine) for 6 months then this happened out of the blue without adding new fish for over a month or so.

What do I do with my remaining 9 neons?? Can anyone advise the best way to treat them, if I lose the 3 showing symptoms does that mean the other tetras in the tank will start to show symptoms and die too?

I have searched the internet and been on other fish forums but no one seems to be able to advise me on what is the right thing to do.

Thanks, any help greatly appreciated