I had a rather large ICH outbreak in my tank and lost a silver dollar and this moring one of my Corys died when he appeared to be ich free. I originally tried methalane blue for nearly a week with no effect then switched to malachite green for several days and was unable to clear up the ich before the silver dollar died. The ich is mostly gone now and any spots that remain on the fish might be wounds from the parasite. I was going to continue adding half doses of the malachite green for a few days to make shure there is not secondary outbreak but the 2 remaining corys do not look particuarly good. They are extreamly sluggish. I was afraid that the malachite may be doing this to them. Thus I put the carbon filters back in and put more methaline blue in the tank after the malachite had cleared * supposably methaline blue is harmless to fish but can kill free swimming protozoan?*. My questions are: Will the malachite green harm the corys and should I use it to make shure all of the ich is gone. And what would any of you suggest that I do to make shure the ich does not come back?