My fish had Ich, and I've been treating them for 4 days with Ich meds, and did a 25% water change and put in some aquarium salt. 2/3 goldfish seem to be on the mend, but the one doesn't appear to have a lot of Ich on it, just patches of blood under the scales and white fuzzy "fungus" on it. How do I treat the fungus? Is this a secondary infection of Ich? Thanks