Cloudy white silver dollar fin

[FSM]

One of my silver dollars has a cloudy white blotch on its adipose fin (second dorsal fin). What is this?

It recently scuffed its body, I assume it ran into a rock or something. I don't remember seeing any damage to the fin though.

 

[FSM]

I am worried this may be lymphocystis, which means I should euthanise the fish, correct? Right now it is a bucket, acclimating to be put in a quarantine tank. The QT tank already has clown loaches in it, with ich. The SD has ich too. I don't want to risk the loaches with an incurable disease.

It looks more like a fuzzy blotch though, so I'm not sure. Any ideas?

 

[Lupin]

Don't perform euthanasia yet. Post a pic of the adipose fin. Does the blotch feel hard or soft? Is it globular in shape?

 

[FSM]

I'm stuck using a 5 gallon bucket for a QT tank, but it should be fine at about 75-76 degrees right?

I'll try to get a picture later, when I took it out of the tank to put it in the bucket I noticed the white blotch was much harder to see.