Question re TA

[onewomanarmy]

Given a vinyl, salt water pool:
I know if you have high TA, you may have a harder time maintaining PH. So the recommendation is to keep TA in the 40-60 range in order to control PH drift.

I guess I'm unclear what TA does in general. Why (again, in a vinyl, sw pool) would you worry about what level your TA is in general beyond just not wanting it to be above 60? Why is a TA lower than that a problem? Would going lower help even more in the PH drift? Or just cause unpredictable fluctuations in PH?

I know, I know, just keep it between the lines, lady. (I just like to understand how things work! )

 

[frustratedpoolmom]

TA recommendation is 60-80 and I wouldn't go lower than 50, because low TA can also cause PH swings in both directions.

 

[Bama Rambler]

The ideal TA depends on your particular pool and how you normally chlorinate. The good thing about TA is that in most situations it tends to self regulate. That is, by adjusting pH when it's needed it adjusts the TA until it gets to a happy spot where you're not adjusting the pH much and therefore not needing to purposely adjust the TA any.

For tablet people the TA usually needs to be about 100 to 130. Us Bleach users usually run a TA of about 70 to 90, and swg users usually have about 60 to 80. It's really wherever your pool is happy though.

The caveat of having the TA too low is that once it gets much below 50 ppm the pH can to swing both directions.

 

[JasonLion]

TA has two different properties. First, and most importantly, it helps stabilize the PH. If your TA is very very low than practically anything can change the PH dramatically. Since we want the PH to stay between 7.5 and 7.8, we don't want it changing dramatically. Second, high TA levels will cause the PH to rise. Our TA recommendations attempt to find a balance between these two properties, so the PH is reasonably stable and the PH doesn't go up too much.

Very low PH will damage the liner and the pool equipment and tends to sting your eyes. Very high PH tends to encourage metal stains and calcium scaling.

 

[onewomanarmy]

I guess that's what I was missing, that it stablizes the PH and doesn't just keep it from drifting higher. I know how important it is to keep the PH in range, so was curious what else the TA does - and it sounds like it would cause fluctuations to not maintain at a certain level. I find all the chemistry interesting, and find that for most of it, it makes sense once I understand what is going on and how they all interact. I'm still (had this problem as far back as high school!) dyslexic when it comes to PH and tend to want to say that my PH is high when I'm acidic and low when alkaline. Of course, I do still have to look at my hands on occasion to see which one makes the "L" to know which is my left and which is my right... (answer - they both do) As a data person, that concerns me sometimes...

Not sure where I got the 40-60 range, could have sworn I saw it on here somewhere. No telling.

Thanks for the info!