Hey guys so I had a velvet out break in July and since then my tank has sat empty of fish and I plan to keep it empty until the end of September to be fully safe. But I have a question of when adding fish I don’t want to add them all at once and then they all get velvet again even though I’ve quarantined my fish this time and prior medicated them if I want to add one test fish how long should I wait to see if it develops velvet before calling it coast clear for the others?