Oh nooo!! Velvet outbreak in sorority!?

[Larsa]

0.o So to all those people who have red my thread about Natsuko's death and how she died early... I think I have a solution...

In my 10 gal sorority, I had 6 females and one of them randomly started acting weird and died. I did a chem test and everything was normal and safe. I gave that tank a full-up water change in 114 F hot water ( left the thermometer in by accident ... 0.0 ) I have been doing water changes once a week for my ten gal. Recently, Sakura-my alpha- has not been eating!! I have tried everything. she is still very active but I saw her scratch. I shined a flashlight on her and OMFG!!!!! Gold-yellow dust!? NOT normal!!! 0-o "oooohhh noooooooo!" Luckily its very early, and the other fish are active and eating like PIGS! * points at Kasumi* Besides doing a full-up water change ( replacing the decorations and rocks as well) and quarantining the females separatly, what can I do!??? My heart CANT bear loosing any more girls T-T I cant seem to get a snapshot of the girls as they are moving around too much...

Do I need to get a copper-based med and use aquarium salt? Im scared because copper is kinda unsafe 0.0

Help. Help. Asap. Thanks in advance!!!!