Total Alkalinity and Free Chlorine

[Reebs]

I have a SWG and a vinyl pool. I see that TFP suggests TA to be on the low side of 60-80 and Free Chlorine to be 3-5. My concern is my SWG manual suggests a range of 110 to 180 depending on the saturation index for TA. They also suggest Free Chlorine of 1 to 3 ppm. Which should I follow? Thanks!

 

[Guest]

They are basing their recommendation on standard industry recommendations that have been found to be 'not quite right'. In fact. their TA recommendation is not in line with the APSP suggested levels as taught in CPO (certified pool operator) courses for comercial pools.
With an unstabilized chlorine source or SWG the recommended level is 80-100 ppm. (for stabilized chlorine, bromine, chloirne gas, and MPS then 100-120 is recommended because these are all acidic).. we have tweaked it down a bit because it helps maintain better pH staibilty. In fact, Goldline (one of the big US manufacturers of SWGs and a part of Hayward) techs are now recommending TA at abut 70 ppm for the same reason.

These two theads might help explain why:
ta-what-is-it-really-t4979.html
water-balance-tips-for-a-swg-t3663.html

FC recommendations are correct for a pool with NO CYA but once CYA is introduced that changes. The industry is JUST beginning to take this into account but the large trichlor manufacturers do not want this information widely known since it will hurt their business. However things that are firmly entrenched in the industry are hard to change. A prime example is the myth that 'slugging acid will lower TA" even though it s been debunked by scientific research!

 

[fuzzy_dba]

I have a SWG and a vinyl pool. I see that TFP suggests TA to be on the low side of 60-80 and Free Chlorine to be 3-5. My concern is my SWG manual suggests a range of 110 to 180 depending on the saturation index for TA. They also suggest Free Chlorine of 1 to 3 ppm. Which should I follow? Thanks!

Welcome to TFP!

It'll help if you read this post http://www.troublefreepool.com/what-we-need-to-know-to-answer-your-questions-t10341.html and add the information to your question.

There are many here with LOTS of experience that will be glad to help with your questions. There are different recommended levels for each manufacturer; some good and some "not-so-good".

Thanks!

 

[poolbee]

I have found that keeping my TA around 90 keeps the pH from drifting up.