Clownfish Swimming In One Place Only

[Mariya]

Hi everyone.
One of my clownfishes in my tank is swimming looking upwards all the time in one place, near the bottom.
What could be wrong? what can I do? I have checked the water salinity - all OK. Also did water tests - all perfect. 20% of water was changed 2 days ago...

 

[WILDER]

Size of tank in gallons or litres.
How many fish and which type.
Can you post water stats please. In ammonia, nitrite, nitrate, and ph.
The make of the test kit you are using.

Does the clownfish look bloated.
Can the fish maintain balance in the water.
Does it look like the tail is weighing the fish down in the water.
What do you feed the fish.
Do you over feed.
Is the fish acting listless and lethagic.
Does the fish tilt to oneside.

 

[Mariya]

it is a 60 litre tank
I have 2 clown fish - 1 is OK
Ammonia 0, nitrite 0, nitrate 0
The PH is 7.9

The clownfish does not look bloated, it just swims in one place vertically (head facing up) It is like it is trying to get higher, but cannot.
I feed them frozen brine shrimp or pellets
I dont think I overfeed, as feed them once daily for a couple of minutes.
It doesnt seem to be tilting to one side, no.

Any help would be appreciated. thanks

 

[WILDER]

if he's have trougle getting to the top of the tank it sounds like a swim bladder problem.

Also feed some shelled peas. Research clownfish diet needs.
Can you issolate and try a bacterial med.