Originally Posted by BrandonCena
i dont have a copper test kit so how much % of water change u think i should do ? ??? and how should i treat the whole tank then
are the fish acting like death is imminent? if not, I would hold off until tomorrow morning when you can go get a copper test and start mixing some water in the meantime while monitoring their current state. if they look like they're dying NOW and you have some water mixed already, maybe change out 5% or somewhere in that range. it's hard to say without knowing the exact level. and even then, maybe not a tremendous decrease. just be absolutely sure you don't overdose and try to dose lower than the instructions call for.
EDIT: when did they first get ich? was it like today? if so, they are likely not going to die from ich tonight. they can be absolutely covered, and it can look bad, but it usually takes a few days to kill them. so when I say, "how do they look?", I don't mean the spots. I mean, how are the fish breathing, swimming, acting in general?