Chem_Geek: Heeeeeeelllllllpppppppp!!!

[LexPlayer]

Once again, are your strips just testing FC? It is possible to have very high TC and the FC low. I suspect that you have a lot of ammonia or organics in the water and a lot of CC has formed. Don't know if the thiosulfate would add to that but it might.

Yes, the strips only measure FC. But here's the thing, after initially adding the neutralizer, the OTO measured zero. After adding only .25 gal chlorine, the OTO measured 4.0 even with a 3:1 dilution. That's seems too high, even for TC.

Anyway, I added a pinch of the neutralizer to a bucket of pool water to remove excess chlorine and then test pH. The result was a deep purple. I didn't think thiosulfate was supposed to do that. I might have to call the manufacturer to find out what the heck they sold me.

PS- I read somewhere that thiosulfate was used to neutralize chlorine for testing and sulfite was used for actual chrlorine reduction in large municipal pools, etc.

Richard, I appreciate the detailed response. Although I have a degree in chemical engineering (15 years ago), it will take me a little while to comprehend the analysis.