Frank wrote, on Thu, 26 Jun 2014 15:31:05 -0400:
> I'm just a retired chemist who was curious about the chemistry.
> I remember as a kid going to public pools that chlorine level was very
> high and pools reeked of chlorine. Today going to a private swim club
> there is no hint of a chlorine smell.
Ah. As a chemist, you might be interested in this recent Time Magazine
news article about kids' pee in a pool creating weapons of war! :)
No, It’s Not Safe to Pee in the Pool, Says Science
"Uric acid from human urine mixes with chlorine to create the cyanogen
chloride (CNCI) and trichloramine (NCl3). CNCI is a toxic compound that
can harm organs like the lungs, heart, and central nervous system."
Heh heh ... of course, the levels of CNCI are low ...
How much pee in a pool would kill you?
What Happens When You Pee in the Pool?
But, back to the desired FC-to-CYA ratio of 7.5%, it seems that every
public health document that I can find lists a minimum FC and a maximum
CYA, but, they don't seem to specify the desired ratio.
It seems surprising to me, since they all recognize that CYA lowers FC
efficiency (i.e., killing time); so, maybe the ratio matters ... maybe it
I follow the 7.5% FC-to-CYA recommendations here for my pool:
But, I'm willing to listen to alternate arguments.