Rotting fin diseases

[Perthegallon]

Hello so I’ve had my clown fish for months and haven’t added a new fish to a tank and probably about 90 days or more but my clown fish seems to have a rotting fin but I qt all my fish before even moving them to this tank and had it under copper and a other substance for type of diseases so could it be something else? I don’t believe the other clown fish as well is picking on him since he’s always been the alpha of the tank

 

[reefwiser]

Generally fin issues start from a fight then infection sets in.

 

[Perthegallon]

Generally fin issues start from a fight then infection sets in.

They are being medicated now

 

[reefwiser]

Great and good luck

 

[Uncle99]

Fin rot can be linked to poor quality water and/or food.