Consistent climbing PH

  • Last Post 13 January 2022
  • Topic Is Solved
MrMedic posted this 11 January 2022

Since the beginning of non-swimming months, my PH has consistently been climbing.   I'm adding 2-4 cups of acid weekly to keep it in check.


All other chems are find.  Checked regularly at unmamed store and using my PoolGuru.


Any ideas on why my PH is always climbing?

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InyoRob posted this 12 January 2022

We'd be glad to help you out. Is this a saltwater pool? What is the alkalinity level?

MrMedic posted this 12 January 2022

Yeah, I guess that would help.   Fresh water pool.

Last pH 7.8

alk 94

cya 75

fac 3.9

tac 4.2

ch 229

tds 1000

pho 0

fe 0

cu 0


I put MA in regularly.  Drops to 7.4 or .5 and steadily climbs by .1 daily.   

MrMedic posted this 12 January 2022

13,000 gallons


InyoRob posted this 13 January 2022

One way pH can climb is aeration that is caused by waterfalls or a spillover. The alkalinity has an impact on the pH as well. Even though it isn't super high at 95 ppm, it can still cause the pH to slowly rise. You could add enough acid so that the alkalinity drops to 80. Then see if that slows down the rise in pH. Some pool owners keep their alkalinity in the 60-70 range, so they don't have to add so much acid.

With that being said, your pool water is technically balanced. Using the Langelier Saturation Index (LSI) is a great way to truly determine if the water needs any adjustment. I plugged your numbers in and used my pool temperature (65°F). The LSI reading was 0.02. Anything within the range of -0.3 and +0.3 is balanced. Here is a link to the calculator I use.

MrMedic posted this 13 January 2022

Well, good news, pool is basically balanced.  
Bad news, Ph still climbing daily. 

I'll try getting the alk down and see if that slows it. 


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