Tiger barb swimming vertically

My tiger barb has been swimming vertically as if she’s struggling to hold herself up. She is very weak and is using plants at the top of the tank to stay afloat. Her appetite is normal. Eyes have a yellowish tent to them as well. Can anyone help? I did a partial water change, changed the filter, made sure the temp was right as well.

 

Definitely a sick/stressed fish.
Can you fill out the sick fish template? It will help us to hopefully figure out what is going on.
Fish Emergency Template | 376562 | Freshwater Fish Disease and Fish Health

 

That tiger barb looks suspiciously like a clown loach? Either that our it's one really sick barb.

 

Definitely a sick/stressed fish.
Can you fill out the sick fish template? It will help us to hopefully figure out what is going on.
Fish Emergency Template | 376562 | Freshwater Fish Disease and Fish Health

What is the water volume of the tank? 30 gallon
How long has the tank been running? 3 months
Does it have a filter? Yes
Does it have a heater? Yes
What is the water temperature? 78
What is the entire stocking of this tank? Just 1 fish. Tiger barb (Please list all fish and inverts.)

Maintenance
How often do you change the water? 2 times since 7/10.
How much of the water do you change? About 30 percent
What do you use to treat your water? NovAqua plus water conditioner
Do you vacuum the substrate or just the water? I don’t vacuum anything

*Parameters - Very Important
Did you cycle your tank before adding fish? Yes
What do you use to test the water? I didn’t test the water.
What are your parameters? I don’t know. But he’s survived in the water even after the water changes for a while.

We need to know the exact numbers, not just “fine” or “safe”.

 

That tiger barb looks suspiciously like a clown loach? Either that our it's one really sick barb.

He’s really sick. It just started happening a few days ago. His color is off and now he’s sitting at the bottom of the tank breathing hard.

 

I

He’s really sick. It just started happening a few days ago. His color is off and now he’s sitting at the bottom of the tank breathing hard.

Would suggest from your other post that you buy some form of test kit or strips and get some readings. That might tell you a lot. Otherwise you're just guessing

 

That tiger barb looks suspiciously like a clown loach? Either that our it's one really sick barb.

Yeah I see what you mean. It’s difficult to really see details but I think it looks more like a thin, bent tiger barb. I don’t think the head shape is right for a loach.

 

More pictures from other angles could help us put the indecision of tiger barb or clown loach to rest.

But as others have said, without knowing water parameters we have nothing else to work off of here.

 

Yeah I see what you mean. It’s difficult to really see details but I think it looks more like a thin, bent tiger barb. I don’t think the head shape is right for a loach.

Yes. It’s definitely a tiger barb.

 

Without having any water test results, I’m just guessing here. There is no way to tell if a tank is cycled without testing. If you do a fish in cycle without testing than water changes are needed multiple times a week. That’s how we did it in the 80s lol!
My guess is the barb is suffering from ammonia and/or nitrite poisoning and/or ph shock if your ph has dropped significantly during the cycling process. Also, do you have cartridges in your filter? You don’t need to change them; just rinse in tank water. A good bit of the beneficial bacteria reside on that filter.
Plus, they may be little jerks to each other at times, but tiger barbs thrive in a large group. Having only one may have contributed to its stress.
Your aquarium details state you don’t know about the nitrogen cycle. Read up in it and purchase a test kit. API is one that most use. I would bet your tank is cycled but the fish was damaged by the process.
You can have a nice group of tiger barbs in your 30. Test that water, put the tank on a weekly water change schedule, and enjoy. And welcome!