Hello i am new to the saltwater hobby i have had my tank for 6 months and i have just noticed today one of my clownfishes dead I am trying to figure out if this is velvet, ich ,flukes, fin rot , or something else. All my water parameters are good i have no aggressive fish
Welcome to the forum!
It would be helpful to know actual numbers for params - good doesn’t tell us anything.
Full stocking would also help - clowns are aggressive fish and definitely a contender for aggression. The torn fins would definitely either be from injury by another fish or your cleanup crew starting to do its job after the clown died.
Post mortem pics generally don’t say anything about disease, symptoms and pics/videos of the living fish plus a full history of the tank and its inhabitants would help a lot.