Is my tang turning into a zombie?

[freddy]

In the past couple of months I bought a kole tang,seemed healthy next day looked terrible,just like that picture you found,started feeding metronidazole and focus in with their food,in about 4 days he looked like a brand new fish,I should have quarantined but didn't,and I forgot to mention my bicolour caught whatever the kole had,both are fine now,meds never affected inverts or corals,I also soak my food in a vitamin supplement and garlic quard,this is just my expierience,thouhgt I would share,does your fish have white stringy poop.