Ok, I've got an engineer goby with spots all over it. These spots are not as sharp and bright white as ich, more of a slimy scuzzy appearance. The fish is COVERED in it, but otherwise acting just fine, eating like a champ, and aside from its appearance, you'd never know it was sick. Today I noticed a single spot on my purple firefish. It's round, and has the same fuzzy translucent appearance. Am I right in diagnosing this as a fungus? If so, would melafix take care of this without harming my inverts (crabs, brittle star and LTA)