If it is Marine Velvet... *Updated*

[apex82]

I am in the same boat and lost 10 fish in a week already... Once they stopped eating they died the next day. However three died in quarantine from what I think was a chemical reaction when using dechlorinator in water with a copper treatment. I didnt know of this as there are no warnings on copper product or the dechlorinator. If you are using tap water, just let the water sit for 24 hours to leach out the chlorine(wont get rid of chloramines however if your area has them in the water). I say get em out asap, its just not worth losing new additions to the tank. I cant believe I have to go 2 months without a single fish in the tank.... crazy