If that happens, you'll need to let your tank go fallow for 60 days (invertebrates only, no new fish). Then, you can reduce the chance of this happening again by either quarantining all new fish, buying only captive raised fish, direct from the breeder, or buying pre quarantined fish from a vendor like Dr. Reef.
Here is a link to our quarantine protocol:
2024 Quarantine Procedures Jay Hemdal David Scarborough Protozoans (Cryptocaryon/ich, Amyloodinium/velvet) and Metazoan trematodes/flukes are by far the most common parasites found on newly acquired fish. A carefully managed, proactive quarantine process can effectively eliminate these...
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Jay