Thio-Trine AKA Sodium Thiosulphate AKA Hypo ppm?

smallpooldad

Well-known member
Aug 6, 2008
429
Honolulu
Question 1: Using the above product to neutralize chlorine at a rate of 1 oz for 1 ppm Cl per 10,000 gallons, how much sulphur in ppm is deposited in a 10,000 gallon pool per oz of Thio-Trine?

Question 1: Does this have any effect on algae either good or bad, or is it neutral, using say 7 oz?

Thanks for any help.
 

chem geek

TFP Expert
LifeTime Supporter
Mar 28, 2007
12,082
San Rafael, CA USA
It doesn't matter. Sulfur isn't a particularly critical element for algae growth. As for the amount of sulfur added, that depends on the concentration of product -- there are many different reducing reactions that can occur with thiosulfate and chlorine so I can't tell what they are assuming. Sulfur is around 32 g/mole while chlorine is in units of around 71 g/mole -- if it takes 4 sulfur for every chlorine then for each 1 ppm FC you get rid of you will have 1.8 ppm sulfur; if it takes 1 sulfur for every 2 chlorine, then for each 1 ppm FC you get rid of you will have 0.2 ppm sulfur. The former is the more likely reaction, but dosing usually assumes less thiosulfate is required.
 

smallpooldad

Well-known member
Aug 6, 2008
429
Honolulu
Chem Geek,

Thank you for the quick reply.

If I understood you correctly eliminatinating/reducing 5 ppm chlorine would create 5 x 1.8 = 9 ppm of sulfur. Is this correct.

Aloha.
 

svenpup

LifeTime Supporter
Nov 18, 2009
835
Sacramento, CA
Maybe the larger question here is why do you need/want to neutralize chlorine?
It is safe to swim at any level less that shock for a given CYA. What are your numbers?