Have you ever failed to kill disease post treatment?

[Miami Reef]

After the QT process we are supposed to watch our fish for 2-4 weeks in non medicated water to ensure no parasites slipped through. It should be non medicated because even below therapeutic copper can cause an active ich infestation to show 0 symptoms.

Has anyone observed their fish, found nothing wrong, but somehow in display they got ich, brook, flukes etc?

 

[revhtree]

Sadly yes but I've always attributed it to my own failure at some point or level.

 

[Jay Hemdal]

After the QT process we are supposed to watch our fish for 2-4 weeks in non medicated water to ensure no parasites slipped through. It should be non medicated because even below therapeutic copper can cause an active ich infestation to show 0 symptoms.

Has anyone observed their fish, found nothing wrong, but somehow in display they got ich, brook, flukes etc?

As mentioned in the other thread, I cannot recall a time where I successfully treated a parasitic disease and then had it return weeks or months later - except in cases where I could identify an issue: disease carried in on new animals, live food, tank tools or even aerosol droplets.
Jay