Sick Neon Tetra! I’m a novice that needs advice

[Kuhlikuhli65]

I had 7 neon Tetras for about a month. About a week ago one passed very suddenly. He was fine till an hour before and his only issue was swimming weird.
Now another is sick and I can’t figure out what it is.
It’s only swimming strange and it’s eyes seem bigger then the others, so maybe popeye? It also gets bullied out of food so I made sure it got some last night and it’s swimming much better so maybe it doesn’t have enough food?
I have kuhlis so I’m gonna take it to a small tank to at least give general cure.

 

[the loach]

It's a runt. He has fin rot and is emaciated as well. The quality of many tropical fish is very poor nowadays. You can try but I doubt you will be able to save it.

 

[Kuhlikuhli65]

I figured it might have popeye just now, haha. I was worried it could be neon Tetra disease, but I don’t think so? I’m not sure, this is the first group oof neons I have had. Also my water is at 0 for ammonia and nitrite. At 10 for nitrate

 

[Kuhlikuhli65]

Okay, thank you! I was so worried it was neon Tetra disease. Yeah I also got him from pet i which I’m learning is not the best for quality of fish unfortunately

 

[the loach]

With popeye the eye is pushed outward, but the eye itself isn't bigger. It's impossible to say which diseases he doesn't carry, best thing would still be to separate him.

 

[Kuhlikuhli65]

Okay cool, thank you! It wasn’t looking like the pictures of popeye when I looked it up but I wasn’t sure, so thank you for clarifying it! Yeah I’ll still separate it