Velvet Question

So all but one hippo tang in my tank has died. Based on the symptoms it appears to have been cause by velvet. If there are no fish in my tank will velvet die off? If so how long should I leave my tank fishless before i add another fish? I have coral and one hippo tang that appears to be not affected by the parasite. I will give the hippo back to the store and leave my tank with just the inverts and coral and LR until all the parasites die off. thanks

 

This link says says 6-8 weeks.

Coral Reef or Velvet Disease, Amyloodiniumiasis, A Virulent Dinoflagellate Disease of Saltwater Fishes

Good luck to you.