Ok, so we should panic over a report of 16 incidents reported to the CDC in a 1 year calendar period with probably millions of operating hot tubs, many of which are poorly balanced? Personally I feel safe in my hot tub, I test the chlorine and pH before each use, have an SWG, an Ozonator, and a Nature2 mineral cartridge (admittedly the cartridge is not changed on a regular schedule)