As to the subject at hand, ozone and negative ions are entirely different beasts. Negative ions are not unhealthy but ozone is.
I've employed negative ion generators in conjunction with hepa filtration to help scrub odor. Negative ions don't make it far from the source.
As far as feeding...
Sounds like your water may be a reliable source of calcium. Try just adding Magnesium sans more calcium or get an RO filter.
Make sure you don't have root aphids.
Condensate collection tray drain port is likely blocked by slime. Shop vac the outlet and see if that clears the plug. Blowing it leaves the plug in the tray....