PH and TA Question

[SultanGuy]

I think I have this under control. But I would appreciate clarification/reassurance...
I tried to raise my PH from 7.4 to 7.6.
My TA was 80.
Using the pool calculator, I added the proper amount of Washing Soda (which also told me the TA would likely rise 6.4)

24 hours later:
My PH went up to 7.5-7.6 (where I'm aiming.) but my TA went up by 25 points to 105. I understand now that 105 TA is not a big problem. But I'm disappointed that it jumped so much.

The big questions:
Should I only worry about TA if PH gets too high?
Should I trust the pool calculator's "Effects of adding chemicals"?

Now playing with the calculator, I see that Borax would have less rise on TA for the same PH rise. But I'm not sure how much to trust the "Effects of adding chemicals" after the rise in TA last time was 4x what was predicted.

 

[JVTrain]

Admittedly, I have never had to intentionally raise my pH aside from when I first took over my pool so I can't personally verify the accuracy of the Effects... in this department. Did you use the calculator at the PoolMath link at the top of the page?

Aside from the unexpected TA increase, you likely didn't need to raise your pH chemically. Simply by aerating your pool more by aiming returns up or running a fountain, your pH would have rose due to the aeration. Aeration increases carbon dioxide outgassing and raises pH, as long as you have sufficient TA, which at 80 you did.

Your current increase TA may lead to faster pH rise going forward.

Borax would have indeed raised your TA by a lesser amount. If there were any other fillers in that specific brand of washing soda, that could be a source of more TA, but most washing sodas are nearly 100% sodium carbonate.

 

[SultanGuy]

I did use the calculator on this site. I may have to get a fountain because the single return doesn't break the surface and is not really adjustable (Intex 15' x 48"). Thanks for input. I'll keep an eye on the PH from here on out. I already have MA if I end up needing to lower the PH to 7-7.2, then aerate.

 

[pookiesunshine]

... I may have to get a fountain because the single return doesn't break the surface and is not really adjustable (Intex 15' x 48").....

not sure what kind of return jet fitting you have, but you can easily make a fountain. search this site for aeration. i made one for similar reason: my TA is too high to add more pH increasers. my pH is slowly rising from aeration but it does take a while.

 

[tstex]

"you likely didn't need to raise your pH chemically. Simply by aerating your pool more by aiming returns up or running a fountain, your pH would have rose due to the aeration. Aeration increases carbon dioxide outgassing and raises pH, as long as you have sufficient TA, which at 80 you did." Per JV Train, this is the answer.

Almost in all instances, your pH will rise w/out doing anything...only way your pH would drop would be in your fill-water was very acidic or more acid than your target pH.