QT Question: Repeat Prazi dose or move on to Copper

[Jay Hemdal Verified Community Expert]

Hey Guys @vetteguy53081 @Jay Hemdal @threebuoys @MnFish1 ,

Sorry to tag you all - I need help.

A couple days past and the Purple Tang now has very obvious skin lesions. Way more than when I last noticed. Could I please get an ID/diagnosis and best course of action?

I was already slowly bringing up copper concentration in the water, but clearly I was being too nice with what ever this is and now it has exploded. Still, Im only noticing this on the purple tang - perhaps it just stands out more on the darker coloured fish.

I only have a Salifert indicator test, and upon testing, I couldn't pick up any copper (i.e concentration is less that 0.1ppm). Therapeutic range is 0.15 - 0.25PPM for the copper I have. I have added more copper tonight and will retest in a couple hours to see where I'm at.

Still swimming fine and has a pretty ferocious appetite.

A kid at my LFS told me he feeds his fish raw garlic chopped up - Any good?

Please see video/images below

That is Cryptocaryon, ich. You are using ionic copper, and that is always tricky. You need to get to 0.18 to 0.20 ppm as soon as possible. You will then need to test and redose daily, or even twice a day in order to stay in that range. I would treat for 14 days beyond the day when the spots disappear. I don't run ionic copper for 30 days, 21 days at most.

Jay