Is there anything else I can do?
Yes - based on the fish's history, I would consider a praziquantel treatment. That's safe for your invertebrates, and will treat for possible flukes:
Dosing Praziquantel (PZQ)
Using Praziquantel (PZQ) to treat flukes Overview In the early 1990’s, a researcher at the New York Aquarium published a paper on using Praziquantel (PZQ) to help control flukes, a parasitic flatworm. Also known as monogenean trematodes, these fish parasites can cause significant mortality in...
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