SWG and TA

[tunacan]

I've recently installed a SWG, and I'm still sorting out some questions (I just posted another thread on testing and cold water).

I read here that TA should be between 60 - 80 with the note that "this is important". For as long as I can remember, my water's TA has been around 120. If memory serves, I need to lower PH to 7 with acid and then increase PH with aeration to lower TA.

1. Why is a lower TA so important?
2. Do I need to lower TA using the acid/aeration method? Is that the only method?
3. I get a lot of PH rise...will lowering TA stabilize my PH?

Thanks!

Ron

 

[JohnT]

The biggest reason for lower TA levels in a SWCG pool is that it helps stabilize pH at lower levels and reduces acid demand.

Acid followed by aeration is the only way to lower TA without it rebounding. The acid additions you make for your SWCG are going to keep lowering the TA slowly over a longer time period. If you want to rush it, do the aeration and then hit it with acid again and repeat to ratchet the TA down.

 

[tunacan]

Thank you John...very helpful!

Ron

 

[jblizzle]

This process is described in Pool School here: Lower Total Alkalinity

Like John said, there is not hurry to do this as just normally maintaining the pH in range should bring the TA down.
What is your top-off water's TA? If that is high, then you will unfortunately always be dealing with the faster rise of the pH due to higher TA.

 

[tunacan]

Ah, good point Jason...my top off water does have a similar TA of 120. Might just be something I have to deal with..

Ron

 

[linen]

My top off water is much higher than that, so when I add a significant amount I have to use the aeration technique mentioned to get it down.

I am not sure this was mentioned explicitly above but, the swg itself will tend to drive your ph up. In addition, having high TA can increase the risk for scaling of the swg cell.