for the sick fish lower the sal to 1.018 and raise the temp to 82 in QT add formalin and also add a air stone to QT. I read on a site the other night this guy helps people that email him and this is what he recommends for most ailments. Do not use copper with angles and tangs unless you have no other choice as in MV. The copper kills a organism in their stomach and then they have a hard time digesting food.
I have been reading on many sites about sick fish right now I don't know why. Maybe wholesalers are not QTing before shipping to us up here right now supply and demand you know.

Bill