Toss in DT or re-treat?

[Spar]

I had an unfortunate bout with velvet that wiped out most of my fish. The two survivors, a Purple Tang and a Bangaii Cardinalfish, were treated with Chlorquine Phosphate for 30 days, and have been in QT for an additional 45 days or so since (75 days total now). So I am relatively confident I wiped out any issues with the fish.

I have since then become more familiar with the recommended process of treating fish with CP. The fish have been in the same tank during and post-CP. So if any velvet cysts released after the 30 days of CP treatment then the fish would be infected again.

My concern is that given that these fish are obviously relatively resistant to velvet that they could be carriers again. There are otherwise no signs of velvet on the fish. Should I assume I have done all that is necessary and pop them into my fallow-treated DT, or should I re-treat the fish with this time doing a single TTM before removing CP from the water column? I am [obviously] gun shy with this after going through absolute hell a few months ago.

 

[ihavecrabs]

@4FordFamily
@HotRocks

 

[Crabs McJones]

Did the DT sit without fish for the 75 days? If so you're good to go, all traces of the parasite should be dead. And if they went through 30 days of CP and 45 of observation without incident it's safe to say you wiped out the parasite. Just be sure to quarantine and treat anything new incomming

 

[Big G]

You could do the Black Molly test.

https://www.reef2reef.com/threads/f...-vs-marine-fish-diseases.312166/#post-3843490

 

[bluprntguy]

It would have been better to transfer to a sterile tank after CP, but I think the risk of the fish being re-infected and now immune after you removed the CP are pretty slim.

If you really want to be extra cautious, you could re-treat the quarantine for 10 days and then move the fish straight to the display tank.

 

[4FordFamily]

You could do the Black Molly test.

https://www.reef2reef.com/threads/f...-vs-marine-fish-diseases.312166/#post-3843490

This would be my advice!

 

[Spar]

You could do the Black Molly test.
https://www.reef2reef.com/threads/f...-vs-marine-fish-diseases.312166/#post-3843490

You mean adding the Black Molly to the QT as a test?

Did the DT sit without fish for the 75 days? If so you're good to go, all traces of the parasite should be dead. And if they went through 30 days of CP and 45 of observation without incident it's safe to say you wiped out the parasite. Just be sure to quarantine and treat anything new incomming

Yes, it has been fishless for around 80 days now. I just wish I had switched to a sterile tank just prior to dropping the CP... I think I am going to re-CP the QT for a couple weeks instead. I really can't risk this. Seems quicker than doing the Black Molly approach, and these fish did just fine under 30 days of CP.