I did not notice what species we are talking about here, but if it is ick, I would rocommend Jason's method of the hypo with the copper. I did some research, and it did not sound to be safe. But after trying a few methods of treatments, my lion seemed as if he was a goner for sure so Jason's method was my last hope. Sure enough, within days my fish was improving and the treatment took only about a week. Its been several weeks now since my fish has been back to normal and would recommend Jason's treatment if your sure it is an external parasite. I'm only new at this, so I am just adding what has worked for me.