Almost lost gold barb

[FishRus]

I have 3 gold barbs (getting two more soon) two of them are pretty big and the other one is much smaller. I'm not sure if he is just the male or if there is another problem but anyways for some reason his mouth is messed up and it's been like this for about a month now and yesterday he was lying on his side and could barley swim or do anything. I did a quick water change and about a hour later he was fine? I thought for sure he was a goner but he seems to be doing fine now. No idea what the problem was... My water parameters are fine. His mouth is always bloody and almost looks like he's missing him bottom lip. No idea why it's like that either. My fish are never aggressive towards each other so I'm basically clueless on why it's like that or why is almost died....

 

[T1KARMANN]

I have 3 gold barbs (getting two more soon) two of them are pretty big and the other one is much smaller. I'm not sure if he is just the male or if there is another problem but anyways for some reason his mouth is messed up and it's been like this for about a month now and yesterday he was lying on his side and could barley swim or do anything. I did a quick water change and about a hour later he was fine? I thought for sure he was a goner but he seems to be doing fine now. No idea what the problem was... My water parameters are fine. His mouth is always bloody and almost looks like he's missing him bottom lip. No idea why it's like that either. My fish are never aggressive towards each other so I'm basically clueless on why it's like that or why is almost died....

What barbs are they

 

[FishRus]

What barbs are they

Gold barb

 

[Khuligirl93]

What size tank?
What other fish are in it?
How long has it been set up?
What were the ammonia, nitrite, and nitrate levels when you tested the water?

 

[T1KARMANN]

Gold barb

You can get different gold barbs

Gold tinfoils
Gold tiger barbs

To name a few one gets massive the other stay small