URGENT HELP! DYING CHANNA BLEHERI

HELP!
My new Channa Bleheri appears to be having breathing issues.
It's 4" in a 17.5g tank (1ft water depth)
pH 6.6, Amm 0, Nitrates close to 5ppm
Water temp 26°C

Now reduced to 2.5" water level, did a water change, introduced in 1 air stone and 1 air stone disk.
I do not have any pimafix/melafix.

It was doing well the past 15 days, until now. It has all it fins flared out the whole day and did not want to eat.

I noticed it swimming erratically for a bit, then it went to the water surface (around half it's body above the surface). Then it went down and did not move much.

It looks to me it's having breathing issues (have some hiccups?, and also tend to fall/tilt its body towards the right.

Still appears to be struggling, and will have sudden burst of movements occasionally.

Any advice would be appreciated! Thanks.

An immediate waterchange - 50%.
Then daily for a couple of weeks.
Pimafix and melafix aren't really meds. They would not have helped.
It's a big fish for a tiny tank. Is it all cycled? I'm not one to blame the cycle for much, but that fish is solid.

I believe Channa are air breathers, as well as being able to process oxygen from water. But I have never kept them, as they're illegal on my continent. Sorry I can't help more.

GaryE said:

An immediate waterchange - 50%.
Then daily for a couple of weeks.
Pimafix and melafix aren't really meds. They would not have helped.
It's a big fish for a tiny tank. Is it all cycled? I'm not one to blame the cycle for much, but that fish is solid.

I believe Channa are air breathers, as well as being able to process oxygen from water. But I have never kept them, as they're illegal on my continent. Sorry I can't help more.

Click to expand...

Thanks for the advices GaryE.
Yes it's cycled, with 0, 0, ~5 readings.

For now it's in a 2ft as a juvenile. It's condition looks like it's deteriorating, I hope it will last and recover for me to do the wc next few days