arg,
it happen to me too....even u use the most high tech equipment. There should b a source of the outbreak
As for me, it happens twice even when im running ozone and i quarantine all my new fishes. Some says that is a new tank syndrome.
funny thing is, we share the same fate.....the last few outbreak, the earspot angel survives...thats a good sign as it is one of the most expensive fish
hope u can overcome the outbreak. Part of parcel of keeping fish