Question on Quarantine new fish

[Lance0964]

Hi,

I'm new in this hobby. My new fish has been in quarantine tank for two weeks. However, a wrasse dead on the third day after add Prazipro, and two blennies dead in Cupramine…. I noticed those are kinda sensitive fish after they dead.

My question is, how to quarantine sensitive fish if they do have parasite and can't take the treatment like copper? And also, is there a list showing which fish are sensitive to copper?

Other fish are doing good. Two clown, fire fish, and a hippo tang. The hippo tang had really heavy ich and didn't eat, but he's getting better after one week with Cupramine and start eating.