White specks and fuzz near mouth on a white molly

[KaitieG]

I purchased several giant sailfin mollies from an LFS a week ago.  They're in QT right now with guppies and corydoras.  Have treated with ParaCleanse.  I've never had issues with fungus/ich before, so usually just watch for those before treating in QT but always do parasites with livebearers.  The white male molly started periodically swimming vertically last night and I see that there are some raised white dots along fins and body.  Also now has fluffy looking growth near/in mouth with a red spot in mouth.  He is eating when I feed (sparingly), but definitely not looking great.  Hard to get a picture that's even halfway decent with the white on white.  Everybody else in the tank looks good so far.  Parameters are stable, and I have extremely hard water (like the color is off the charts on the coop strips hard), so I was hoping I'd avoid some of the issues with mollies transitioning from brackish water.  Thoughts/suggestions?

[Colu]

With raised white spot could be epistylis that feeds off of gram negative bacteria on the slime coat of your fish and spreads more quickly at temperatures over 75°F  what your describing with the mouth could be a secondary fungal infection most effective treatment would be maracyn2 in food feeding a small amount twice a day for 7 days and treat the tank with ick x @KaitieG