Clownfish sick- very severe

[Tom-nanoreef]

Clownfish is barely moving, doing flips/swimming very erratically in bursts, breathing really heavy and its mouth is white, so is its top fin (not as white).

Ive had the tank for a 1 year and a half, the fish until march. There are no other fish in the tank. Yesterday, it was laying at the bottom of the tank. The fish had been occasionally at the bottom of the tank in the past and I had seen it “seize” a little every once in a while, I hadn’t thought much of it. It did not want to eat yesterday. I woke up today and it had worsened a lot, started doing flips and having a hard time swimming.

Parameters:
Ammonia - 0
Nitrate - 0
Salinity - 1.026
Nitrite - 0
Alkalinity - 7.1/7.2

Aquarium - old biocube, 13 gallon, lid is new biocube lid, everything including flow has been replaced

 

[Mr. Mojo Rising]

Dude, thats a very dirty tank. My first thought would be too clean it out and do a couple 80% water changes. Poor fish...

 

[Lavey29]

Agreed, that's a filthy environment for a fish.

 

[Celestion]

remember all that debris in the water column degrades the fish from breathing , algaed over glass is not good for fish well-being