Ph and Chlorine Question????

[Sid/]

I don't know where I read this. Maybe on the TFP site or another group. The statement that I viewed was that your chlorine that you put into your pool would do more for your water if the PH was at a lower PH level like 7.2 or so instead of 7.8. When I say more for your pool water I'm saying a better reaction on the chlorine to kill more contaminates. I'm just wondering if this is true or not??? Thanks TFP for a crystal clear pool.

 

[Richard320]

Quoted:

pH does affect the active chlorine (hypochlorous acid) level that is responsible for most of the disinfection of the water. However, when Cyanuric Acid (CYA) is in the water, it buffers this active chlorine so that pH has far less of an effect on it. To be specific, with no CYA in the water, going from a pH of 7.5 to 8.0 has the active chlorine level drop by 50%. With CYA in the water, it drops by only 15%. Going the other direction, going from a pH of 7.5 to 7.0 the active chlorine level with no CYA increases by a little more than 50% but with CYA in the water it increases by 35%. So we generally ignore the pH effect on chlorine except for a SLAM because the larger amounts of chlorine have the pH rise significantly so we recommend lowering the pH first before a SLAM, especially when it's a lot of FC due to high CYA levels.

Chlorine and pH relationships. Chem experts knowledge?

OK, so I am a newbie. But, I’m ignorant of pH within Chlorine relationships. I can find very much data here on Chlorine/CYA, but what about pH? Basically without getting too technical……haha, (I’ve read Chem Geeks articles) I am trying to figure out the effectiveness of Chlorine at different pH...

www.troublefreepool.com

 

[Sid/]

Thanks Richard for your response. I try to keep my cya near the 30 and 40 range ppm. So from your response with my CYA level of 40 just mark off another concern of how my chlorine reacts to the water to a lower PH level. It seems my water likes 7.6 to 7.8 PH, so I'll stick with that and not lower the PH too much. Thanks for the Chem Geeks link... will take a look,,