Low TA and high ph - acid or baking soda first?

[DowneastSpa]

As stated in the title. I have a ta of 50 and a ph that is touching 8 and drifting up. Do I add muriatic acid first, then a touch of baking soda to get the ta back to 50ish? Or should I first add baking soda to bring ta up, then muriatic acid until it holds at 7.6 after aeration?

Yes I have boric acid on order from duda diesel, trying to get everything in line for when that arrives.

 

[willygee]

I know in my pool i get alkalinity established allowing a couple of days and then lower ph. Alkalinity stays pretty steady...ph rises after rain and then i add a little MA.

 

[jark87]

My pH rises fairly quickly but TA remains relatively steady. I’d recommend lowering pH first. I have a SWCG and find keeping my TA in the 50-60 range helps control the pH rise a little - at least it doesn’t rise as fast as it did when I was keeping TA in the 70-80 range. I still add muratic acid once a week, but not as much as I used to. pH is much easier to lower. If you find that your pool works better with TA in the lower end of the range, but you raise it up first, it’s harder to bring down, at least for me it is.

 

[generessler]

All I've read says adjust TA first.

In this case, that goes double: 50 is around the point where pH becomes unstable. That's bad. If you add acid first, it will go even lower. Also bump FC to the top of the range until the pH is under control. High pH makes FC less effective.

 

[CuckooChris]

I may be doing it wrong, but I rarely test my TA. From everything I've gathered here, PH is the most important. After reading this thread last night I decided to see what my TA was and measured 40, Ph 7.5. I test FC every day and PH every two or three days. My Ph does slowly creep up, so when it gets up near eight I ad MA or dichlor to knock it back down. I have never seen wild swings in my PH but haven't tested after a soak either. I'll have to check next time.

 

[duraleigh]

Lower pH - use muriatic....TA also comes down
Raise pH - use borax.....it has little effect on TA.
Lower TA - acid and aeration method....see Pool School
Raise TA - use baking soda....it has little affect on pH

Always good to review that. The order in which you change them is not overly critical.

Over the years, TFP has lowered it's TA suggestions to roughly 60-90.......it used to be 80-120

pH suggestion remains 7.2-7.8 and is quite a bit more meaningful to the pool owner than TA