Butterfly with withe spots

[Alcasrac]

hi All,
I got the butterfy copperband a week ago.
On the last couple of day i find white spot but now bit more. Do i need worry about?

 

[HotRocks]

The spots on the tail are likely lympho.
https://www.reef2reef.com/threads/lymphocystis.257461/

You may want to do a FW dip and check for flukes as well.
https://www.reef2reef.com/threads/freshwater-dip.248898/