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Thread: pH still increasing daily 1 yr after new plaster

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    pH still increasing daily 1 yr after new plaster

    Our pool was replastered a year ago (March 2014). I was told to expect pH increase and large acid demand as the plaster cured. Reviewing my notes from last year, I typically added 2 cups of muractic acid daily to keep the pH around 7.5. This was continued up into the fall. During the fall/winter/spring my acid usage dropped significantly. I may have added 2 cups of acid weekly. Now that summer is back, my acid demand has crept back up. I am now adding 2 cups daily or every other day. I'm trying to maintain around 7.5

    Here are my current test results using the TF-100 kit.

    CC= 0
    TA=70 (This number has ran around 50 all winter. I just boosted it to 70 recently and that is where it ran before replaster with no pH swings)
    CH= 190 (This has typically ran between 210-230 since replaster. This is lowest result I have had)
    CYA=25 (this is purposely low because I will be on vacation and using the trichlor tabs next week)

    Is this typical for pH? Some of the posts I searched mentioned curing in a month or within a year, depending on method used for startup. I'm concerned that I may harm the new pool finish if something is not allowing the plaster to cure. Is the low CH a problem as well?

    I use the BBB method and have never had to SLAM the pool since refilling in March 2014. I've only added algacide once because I took the FC to zero to do an absorbic acid treatment for iron staining back in October. I do add a dose of metal free weekly to prevent staining because I noticed in spring that iron was starting to deposit on sides again. Other than that, I don't add anything else to pool besides bleach and acid.

    20K IG gunite
    TR-60 Sand Filter, 1HP Pentair single speed pump
    Memphis TN

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    TFP Guide

    Azgirl71's Avatar
    Join Date
    Apr 2015
    Sierra Vista, Az

    Re: pH still increasing daily 1 yr after new plaster

    I have seen people who have PH rises a couple years after new plaster. So I would say it is normal, but should slow by the end of the season.
    Intex AG vinyl 15' x 48" 4,300 gallons due to skimmer install, Krystal Clear SF pump combo 2800 GPH, Krystal Clear SWG, Pool Blaster Max vacuum, Hayward thru the wall skimmer, TF 100 test kit with speed stir, K 1766 Taylor salt test, My SLAM Process

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