Velvet Treatment in Display tank

[merlinpi]

i have a 76 gallon that was set up 5 months ago, had a clown fish, canary blenny, royal gamma, that were quarantined for 80 days introduced about a month ago, and, at the same time, i moved a blue tang 7 years old from my 7 year old tank that had nothing introduced into it for 6 + years ( i am following its growth on tank size).
I also introduced 5 weeks ago 3 small coral frags that were dipped in CoralRx prior to introduction.
woke up to blenny and gamma dead, clownfish covered with velvet, and tang with some velvet.
tang is too big for my QT, and besides, impossible to catch without further hurting it.
so I took the decision to remove corals and CUC to QT, leave live rock and treat with melaplex, Cupramine, selcon, and garlic. I also increased temp to 79 to hasten cycle of parasite.
symptoms improved after 3 days, both fish are eating well, normal activity and so on.
i am planning to treat with Cupramine for 30 days as i kept the levels of copper on the low side 0.16-0.18 ( i have a peppermint shrimp that would stubbornly also escape me in in the rocks, still alive and well day #12 of treatment).

the issue:
1-can fish be asymptomatic velvet carriers? so if after treatment i introduce other fish (of course yes after quarantine), they can get it from those 2?
2- i will have the task of removing copper from the DT where they are treated (yay). planning giant water changes, cuprasorb, carbon, and triton Detox, close follow up on copper levels (Hanna HR), and reintroducing corals, invert after 2 weeks of 0 levels. Anyone has any input/experience in this?

 

[Dr. Reef]

I would disacrd the rock and sand if posible or strip them with acid before taking any chance using them in a reef tanks for corals. Rocks and sand can leach back copper they absorbed at sometime, no set time line but eventually they will.
Using methods mentioned in your post will only remove copper from water and not rocks or sand.

Something had to fail in your qt protocol or one of the pre existing fish could have been a carrier or your tank could have been infected to begin with. Stress of adding many fish could have triggered parasite population to explode and fish immunity to go down making them less resistant to velvet.

 

[Uncle99]

I would think the use of the copper treatment would have compromised your rock and sand but I’m not convinced that significant absorption would result in short term contact.
Replace sand.
Put rock in a tote with good flow for now.
This should help wash them up.
Test the tote for copper in a week.
Velvet can be a PITA.
Kill it.

 

[merlinpi]

I would disacrd the rock and sand if posible or strip them with acid before taking any chance using them in a reef tanks for corals. Rocks and sand can leach back copper they absorbed at sometime, no set time line but eventually they will.
Using methods mentioned in your post will only remove copper from water and not rocks or sand.

Something had to fail in your qt protocol or one of the pre existing fish could have been a carrier or your tank could have been infected to begin with. Stress of adding many fish could have triggered parasite population to explode and fish immunity to go down making them less resistant to velvet.

the quarantine was 80 days, i didn't treat prophylactically with anything, just kept frequent water changes in QT, it is completely isolated, different python drain, different tools, and different testing bowls. I assumed incubation period for any fish disease would be shorter than this. Hence my suspicion that a fish was probably carrier, and at that moment do we know how long can they be carriers? Because if a fish can be carrier indefinitely, i would question the whole quarantine unless i would treat with copper.