As he said read the sticky and treat them fast. All fish need to go in the 30 gallon. A 30 day observation is not enough, because many fish stores run low level copper in their system. This hides symptoms for a couple weeks. Most of reef central believe you should always proactively treat. I would guess ich probably made it in your tank as well. So leave your tank empty for 3 months. While that's happening treat for Brook. Then wait a week, treat with cupramime(get a copper test kit), and then finally 2 rounds of prazi pro(1week apart). Make sure the QT is cycled(no ammonia/nitrite) go get some bacteria in a bottle and pour that over a sponge filter. Add an air stone and a power head. An ammonia alert badge with really make your life easy. All new fish should go into the 30 gallon and get treated with copper(or tank transfer method or chloroquine phosphate) and then prazi. And then wait a week or two for observation. I would also make some salwater ready in case you need to do a water change.