Velvet

[Carterplr]

How long do you wait before adding fish ro a tank that had velvet?

 

[Sharkbait19]

After infection, a tank should remain fishless for 60 days to ensure all parasite have died off.

 

[Carterplr]

What if I have survivors I can't catch? I treated 20 days with Reef Medic.

 

[Sharkbait19]

What if I have survivors I can't catch? I treated 20 days with Reef Medic.

If you can’t catch all of the fish for treatment, then the disease can still survive, opening up chances for infection.
All reef safe meds tend to be dosed at a concentration that makes them ineffective, so it is a necessity to treat all fish with copper.
Keep trying to catch them.