If they had ich it would be the cause, but and I know Fish'o and others are going to disagree with this but once you are going to use these malachite green etc based medications, and you have to use it half strength as not to affect certain fish/plants/invertebrates, the efficacy against pathogens goes down as well, on other words, it's going to take longer. Personally, I am glad I found something better, and am never going to use those old school products again, at least not in a planted/community setting.