I removed all four Tangs (powder Blue, Unicorn, Yellow, and Kole). Placed them in a quarantine tank, and treated with Seachem Cupramine.
Unfortunately, 16 hours later the Powder Blue, and Kole tangs both died. They exhibited physical signs of Ich.
The Yellow, and Unicorn Tang survived.
I discontinued use of the product, and both Yellow, and Unicorn are now in my sump.
In addition, I did a 50% water change (Sunday, 22nd).
Start using my UV sterilizer again.
All the other fishes in the tank seem to be fine, and exhibiting no signs of ich.
I am a little hesitant about treating the entire tank for the following reason.
It's primarily a fish only tank, but I have live rocks with few pieces of corals.
Not sure what effect the ich treatment may have on my refugium which is now fully cycled, and beginning to show some benefit in controlling Nitrates, and Nitrites levels.
Looking forward to your recommendations.
Thanks,
Mike