[ThRoewer]

Originally Posted by luke1234

many thanks for your help
The skin on my fish has been absolutely clear and have shown none of the signs of velvet apart from the loss of appetite.
There have been no flicking or swimming into high flow areas to clear gills.

If i was to catch my gobies and put them in quarantine how would you recommend treating them even though they have no sign of infection.

while my reef is fishless how do you think i should treat this to clear it of whatever is killing all new fish within 3 days.
thanks again

The best medication against velvet is Chloroquine Phospate, but good luck finding that these days.
Copper usually works as well but there are copper tolerant strains of velvet that can handle dosages that would be lethal to fish.

Amyloodinium is in part algae and can live on photosynthesis for weeks without a fish. But they need fish to multiply. Also, as algae they are on the menu of many filter-feeders, pods, rotifers,... it will be hard for them to survive a single week.
That said, it would be best to leave the tank empty for at least 2 months to be on the safe side.