Quote Originally Posted by CarlD View Post
Evan,
Fascinating! Even Chem_Geek should be impressed!
I was a chem major in college also! Switched after 3.5 years and got my degree in another area. I do understand the technical stuff.
Now a question from a non-chemist: When you add lye (Sodium Hydroxide) a big chunk of sodium ions are released. Don't those combine with the FC in the water to create NaCl, salt? Can't that effectively bind up chlorine ions in the water?
Well, chloride ions (Cl-) would form salt with the sodium. Chlorine in the water is in the form of hypoclorous acid (HOCl) and Hypochlorite ions (OCl-). (And clorinated isocynaurates if CYA is present, plus the various forms of combined chlorine.) If the sodium combined with the hypochlorite ions (which doesn't reall happen in solution) it would be sodium hypochlorite. I am sure you recognize that name!
If the level of salt formed from the sodium and chloride ions formed when the chlorine is used up by sanitizing (reduced to chloride ions after giving up their oxygen) was a problems then you are talking about TDS and a SWG system would be having major problems. We've talked about that before time and again in the forum.
 Just a thought!
Hope this clears it up.