you can't treat the main with any good meds then. If you want to do it right yu really need to get a qt
tank (at least 20 gallon ,don't know the size of you fish). You can get one pretty cheap. As a plus you would then be able to qt
new arrivals and keep this stuff out of your system.
Leave the tank void of fish for 6 weeks will kill off the parasite due to the lack of fish host (inverts are not hosts).
In the qt
tank you could treat with hyposalinity. Blennies are sensitive to copper.
The problem with treating the main:
If its 'reef safe" it is not strong enough to kill the parasite. If the med is strong enough to kill the parasite, it will kill your inverts, coral, etc.
Your call, but reads some posts below. This will support my position and help you with procedure.