Rosy barb seems to be breathing rapidly

[Docoboy]

Hello. I'm new to keeping fish. I have a 100 litre tank with nine Rosy Barbs. Eight of them are swimming happily. One seems to be struggling. He is staying in the same spot, near the bottom of the tank, partially hidden behind a rock. He has more mouth movement than the others, like he might be sucking in air. The ammonia, nitrate and PH levels have been tested by me at home, and also by the aquarium shop, and are normal. About three weeks ago (soon after the fish arrived) there was a brief spike in the ammonia levels but things returned to normal. I'm wondering if he might be physically ill or if it might be stress. There doesn't seem to be any dominant behaviour from the other Rosy Barbs. Not sure what I can do to help him. Would be grateful for any advice or info. Thanks.

 

[Colin_T]

Is the fish eating?
What does its poop look like?

Do a 75% water change and gravel clean the substrate and see if it helps. If it doesn't help and the fish has stopped eating, it is dying and should be euthanised.

Make sure any new water is free of chlorine/ chloramine before it's added to the tank.

 

[Docoboy]

Is the fish eating?
What does its poop look like?

Do a 75% water change and gravel clean the substrate and see if it helps. If it doesn't help and the fish has stopped eating, it is dying and should be euthanised.

Make sure any new water is free of chlorine/ chloramine before it's added to the tank.

Yes, the fish is eating. And actually seemed to be doing better today – swimming around (sometimes). Thanks for the advice – will keep an eye on it and fingers crossed for the best.