White patch on clown

[Jen1234]

One of my clowns has a white patch this morning. I didn't notice this at all yesterday. I don't have a quarantine tank. Can someone tell me what it is please.

 

[HotRocks]

Looks like Brook. I would move all fish to QT and treat with Metroplex for 10 days.

DT will need to be fallow for 6 weeks to erradicate Brook.

https://www.reef2reef.com/threads/brooklynella.247938/