PH always high... cant seem to get it lower

krishmk

Active member
Aug 17, 2017
37
Chandler
Last week when I checked PH it showed almost 8.5 or even higher, pinkish color. Immediately, started adding MA, 28 oz first day. Tested again the next day and still high pinkish color, so added another 28oz.

Third day PH showed the same and then I tested TA, which showed 120 for a semi salted cemented pool (water is salty due to using liquid Chlorine for the past 3 years), 12,500 gallons pool.

So far I have added 128oz of MA, 12.5%, I think from HASA, and the TA only dropped to 105-110 range, PH dropped to 7.3ish range. Temps are hovering around 110 to 118 for the past 20+ days, going down a bit and pool is running 10 hrs a day and is aerated daily.

Whenever my PH was high, it took few days to get is under control, but for some reason this time its taking a lot of MA.

Anyone can give me pointers on what I am missing?
 

bmoreswim

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Jul 16, 2012
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The pH scale is logarithmic. 9 is 10 times higher than 8. And you don’t know how high yours is because of the testing max. You only needed more MA this time because it was higher than before, straight science. But you are keying in on the issue. Your TA is high which is allowing your pH to rise easily. By adding MA and lowering pH to 7.2, then raising your pH to 7.8 or 8 by aerating, then repeating multiple times, this will lower your TA which will allow your pH to become more stable.
 
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krishmk

Active member
Aug 17, 2017
37
Chandler
The pH scale is logarithmic. 9 is 10 times higher than 8. And you don’t know how high yours is because of the testing max. You only needed more MA this time because it was higher than before, straight science. But you are keying in on the issue. Your TA is high which is allowing your pH to rise easily. By adding MA and lowering pH to 7.2, then raising your pH to 7.8 or 8 by aerating, then repeating multiple times, this will lower your TA which will allow your pH to become more stable.
I think I am in the right path, but just wondering if I am missing something. Hopefully within the next week I should be able to get the PH under 7.5 and steady...
 
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krishmk

Active member
Aug 17, 2017
37
Chandler
Finally bought TA from 120 to 80 and it took 3 gallons of MA and lots of aeration in 2 weeks.

I cannot seem to find the TA range.. or I am not looking harder...

Anyone have a range scale that TA needs to be in between?
 

Rattus Suffocatus

Silver Supporter
Jun 5, 2019
1,206
Corona de Tucson, AZ
I am constantly fighting TA here with my water. I am also in Arizona. (and likely my water is better than your is for hardness and TA). If you make this work somehow (especially down to 60!) let me know how you did it. I add a lot of acid now with the pool and the fill water alone brings the TA right back up here. I am thinking about designing an acid injector to add to the auto fill line, it's that bad.

I have my detached hot tub in the 70 region now for TA, but it took weeks for me to get it there and it's MUCH easier to aerate it.
 

bonsey

Well-known member
Oct 7, 2018
82
PA
Aerating increases pH. If you already have high pH, you do not need to aerate when you add MA to lower TA. Just add the MA and let the ph come back up on its own unless it's super low.
 

bmoreswim

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Jul 16, 2012
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Aerating increases pH. If you already have high pH, you do not need to aerate when you add MA to lower TA. Just add the MA and let the ph come back up on its own unless it's super low.
Correct. I think the goal here was a quicker resolution to the high TA. But valid point.
 

Rattus Suffocatus

Silver Supporter
Jun 5, 2019
1,206
Corona de Tucson, AZ
So, the problem with adding TA for rising pH is not going too low in pH. If you want to do the job in a hurry you need to drop down as low as pH 7.0 but leaving the pool to come up from that could damage plaster and equipment. Do what you are supposed to do is aerate to remove the carbonic acid from the pool as CO2 (like shaking up a pop bottle!) and then repeating. I personally don't have a problem doing that in my detached hot tub because you just run the bubbles... in my pool it's more difficult. But I agree the high TA water here needs to be cut as much as practical. I think that is why I see SOOO much scaling on everyone's pools here and why I scaled up my SWCG in three months. But having 180 TA fill water sure fights you.

So typically when it's said to aerate with high pH and TA water that is because you can still drop pH too low in the process of lowering TA. And in my case I've always had to aerate to raise the pH back up in the short term.
 

krishmk

Active member
Aug 17, 2017
37
Chandler
Finally got the TA to 60 and Ph to 7.3ish.

Took almost 3 gallons of MA to get here in 2 weeks. I should have aerated like other members were saying, else I would have achieved TA a week earlier with less MA. Lesson for next time.
 

krishmk

Active member
Aug 17, 2017
37
Chandler
Aerating increases pH. If you already have high pH, you do not need to aerate when you add MA to lower TA. Just add the MA and let the ph come back up on its own unless it's super low.
Surprising PH was high to begin with, but a week later TA was still at 100 and Ph was down to 7.4ish. I had to aerate to bring the TA down while adding MA to keep the PH level.
 

krishmk

Active member
Aug 17, 2017
37
Chandler
I am constantly fighting TA here with my water. I am also in Arizona. (and likely my water is better than your is for hardness and TA). If you make this work somehow (especially down to 60!) let me know how you did it. I add a lot of acid now with the pool and the fill water alone brings the TA right back up here. I am thinking about designing an acid injector to add to the auto fill line, it's that bad.

I have my detached hot tub in the 70 region now for TA, but it took weeks for me to get it there and it's MUCH easier to aerate it.
Lots of MA, Aeration, testing everyday and finally in 2 weeks, TA is down to 60, Ph is at 6.3 ish. Now that the weather has cooled a little, Chlorine demand as gone down from 60oz to 32 oz.