Hey I recently ordered 15 damsels 1 Achilles tan a fox face and a russels lion fish. After three days 13 of the damsels died ( some were doa) and the Achilles tang died. Two weeks later the lion fish and fox face are still good. What should I do. Do you guys and gals think it was just stress or a disease. When I took the fish out of the tank I didn't see any signs of ick or velvet, but I wasn't paying close attention. I still have the fish frozen. Thank you for your help. Also the tank is a 70 gallon with established bio media from my main tank which is disease free.
How established was the bio media? Just because you taken some established medium out does not mean it has enough nitrification bacteria. Has the medium in QT recently processed the expected amount of ammonia generated during QT? This is the question, otherwise you were cycling with the fish.
Your problem may be mostly with poor shipping, no fault of yours, but still it is worth studying.
But had all 15 damsels lived your other fish, even otherwise would have done well, may be harassed to unhealthy state. This is a bad choice, but since 13 of them died it was not the reason for the calamity.
It could also be rapidly spreading bacterial infection.
Many possibilities if you have not done enough prep.
For me, QT starts with absolutely enough nitrification bacteria, large enough QT tank for comfort, all fish feeding well, and functional UV to combat bacterial and viral infection in confined space.
