Over the last couple of days one of my neons has stopped swimming around - he mostly just stays in one place - and he is constantly gasping with his mouth wide open. Can't see any other symptoms.

Tank is a 4 gallon, est. 2 months, 3 neon tetras and until recently one betta (currently in a hospital tank having finrot treatment). Params are all perfect, last water change today (50%), fed on tropical flakes twice a day. The two other tetras are fine.

What might be wrong and what do I do about it? Any help appreciated.

Hi Emmahj,

Not sure what is happening with the tetra but it could be related to whatever condition brought on the finrot in the betta.

Hopefully it is not neon tetra disease which in my experiance and reading is uncurable and fatal. The main symptom of this disease is a whitening of the body, usually from the back of the dorsal fin to the tail.

Is it possible that there was either a pH shift or tempetature swing in the tank recently?

Hi Troy, thanks for answering.

There's always a little bit of a pH shift when I do a water change but I don't think it's that causing the problem because the other fish aren't affected at all and the afflicted fellow was panting before the water change. He hasn't been right for a couple of days.

It's like he just can't get enough air - he's constantly gasping / panting. I've increased the aeration in the tank but it hasn't made any difference. I suspect gill trouble - flukes, or maybe other parasites. I was thinking about trying salt at 3 tsps per gallon (added in stages of 1 tsp per gallon every 12 hours).... can neons tolerate salt?

EDIT: I forgot to mention he has also stopped eating today. He showed a bit of interest in the food when I put it in, but just drifted away again rather than eating any. Would it be possible for something to get stuck in a neon's mouth like goldfish get gravel stuck occasionally?

Hi again Emmahj,

I suppose that the tetra could have gotten something lodged in it's mouth but couldn't say with any certainty.

It is sounding like a parasite as you've said or it could be hyperplasia. A salt treatment at this point would be a good idea as it would help in both ridding the fish's gills of both excess mucus and parasites if that is indeed what is causing this. Instead of treating the whole tank you might want to give the affected fish a salt bath using water from your 4 gallon tank to avoid unneccesary shock to the already stressed fish.

Hopefully your little neon pulls through this and thankfully he is in your good care.

Best of luck

Thanks Troy. I'll give the salt a go tomorrow morning.

This morning none of the tetras would eat and the other two are starting to pant like the first one, so I salted the whole tank (4 tsps, 1 per gallon) instead of doing a bath. I will add another 4 tsps in 12 hours and leave it at that - I feel 3 tsps per gallon might be too much for these little guys.

Is there anything else I can do for them? Thank God Augustus was already in a separate quarantine tank so he won't catch whatever they have. He's still battling with finrot as it is.

Maybe I should have stuck to goldfish.