@Qwarex 1y

I personally think you shouldn't do it. Maybe your new fish is carrying ich but its not showing up because of the uv, but after you think the fish is heathy and put it in a big tank, it might trigger an ich outbreak

@skebo 1y

Depending on how you quarantine. Observation only for 78 days? Yes add uv. Weeks of therapeutic levels of copper with 100% water changes? No real value gained by adding uv. Nothing lost, just really no gain. Can you share more info how you qt?