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Thread: TA & PH on new plaster

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    TA & PH on new plaster

    Another new plaster question...


    The pool is finally full. 18,500 gallons was a little larger than my initial estimate. The TA is 130 and PH is 7.2. Should I lower the PH to 7.0 and let the spa spillover aerate to get the TA down. Wet Edge recommends a PH of 7.2 - 7.6 and a TA of 80 - 100 ppm for the start up period.
    25K Pebble, 2 Speed, DE Filter

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    Re: TA & PH on new plaster

    Wet Edge is just about the same as PebbleTec, so it doesn't get a plain plaster/Diamond Brite type of start. Go ahead and aerate. I seen not need to lower the pH at this point.

    Scott
    Owner of - PoolGuyNJ LLC
    Expert Pool and Spa Repairs, Renovations, and Augmentation. Helping people decide what is the right gear for meeting their needs. Expectations Set, Expectations Met, No Surprises.

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    Re: TA & PH on new plaster

    What are the following:

    Calcium hardness
    Cyanuric acid (If zero, are you planning to raise it soon?)
    Water temperature

    Are you using any trichlor or sodium hypochlorite, or planning to soon?

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    Re: TA & PH on new plaster

    Quote Originally Posted by JamesW
    What are the following:

    Calcium hardness
    Cyanuric acid (If zero, are you planning to raise it soon?)
    Water temperature

    Are you using any trichlor or sodium hypochlorite, or planning to soon?

    CH is 80 ppm
    Water Temp is 63 degrees
    CYA is zero (nothing added at this point)
    My plan is to add cyanuric acid and bleach in 2 - 3 days. I'll continue with bleach as needed for the next couple of months and will switch over to a SWG when I replace the equipment.
    25K Pebble, 2 Speed, DE Filter

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    Re: TA & PH on new plaster

    Based on your low calcium, I would not lower the pH any more. In fact, I would allow it to go up to closer to 7.6. If the pH goes over 7.6, then you can lower it back to 7.6, but not lower. As your TA begins to come down, you can begin to raise the Calcium level. I would keep the TA + Calcium at about a total of 250 ppm.
    TA + Calcium = 250 ppm.

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    JasonLion's Avatar
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    Re: TA & PH on new plaster

    You don't want to raise TA or CH very much just yet. As the plaster cures it will raise the PH, TA, and CH levels. You will need to keep the PH under control with acid, which will also help keep the TA from getting to high. Watch how the CH level comes up. You will probably need to supplement it a little, however, if you raise CH too much now, it will end up too high latter on.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
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    Re: TA & PH on new plaster

    Thanks for all of the advice. I'm on month #2 of pool ownership, so I'm definitely a newbie. I've been adding some acid to keep the PH around 7.5 - 7.6. My latest results on day 3:

    pH: 7.5
    TA: 140
    CH: 90
    Water Temp: 58

    I get very little dust when I brush & assume it's due to the acid wash done on the final prep of the pebble surface prior to filling. Does everything look OK to add cyanuric acid and liquid chlorine at some point tonight or tomorrow? Should I use 1.0 ppm for the chlorine level for the next few weeks? At some point will I need to raise the CH level or will it rise enough on its own as the plaster cures?
    25K Pebble, 2 Speed, DE Filter

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    JasonLion's Avatar
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    Re: TA & PH on new plaster

    How long has it been since the plaster was applied to the pool?

    If it has been more than a month, then yes you do need to add CH at this point to get CH up to at least 250. I thought you were in the first month after the plaster was applied. Again, assuming it has been more than a month since plaster was applied, it is fine to add CYA and chlorine.

    If you are on day three, which is how I read your previous posts, then you only want to add a little CYA and chlorine. It is common to use trichlor tablets starting on day three and for the rest of the first month. Trichlor will add both chlorine and CYA and help keep the PH under control.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

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    Re: TA & PH on new plaster

    Quote Originally Posted by JasonLion
    How long has it been since the plaster was applied to the pool?

    If it has been more than a month, then yes you do need to add CH at this point to get CH up to at least 250. I thought you were in the first month after the plaster was applied. Again, assuming it has been more than a month since plaster was applied, it is fine to add CYA and chlorine.

    If you are on day three, which is how I read your previous posts, then you only want to add a little CYA and chlorine. It is common to use trichlor tablets starting on day three and for the rest of the first month. Trichlor will add both chlorine and CYA and help keep the PH under control.
    Plaster was applied last Thursday (11/17), acid washed on Friday and filled overnight into Saturday afternoon. I still have a bucket of 3" tabs I can throw in a floater instead of the CYA/liquid route for the next few weeks. I didn't know if it would be easier to get the CYA right without the tabs as I want to go BBB with either liquid or a SWG once the start up is complete.
    25K Pebble, 2 Speed, DE Filter

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    Re: TA & PH on new plaster

    With Wet Edge, there is a lot less of a cure time because reduce amount of cement has hydrated, especially since the over night period of being empty allowed this process to speed up. If you pH, alk and CH are holding steady, it should be OK to start adding calcium, powdered CYA in a white cotton sock in from of a return and or in a skimmer and a little bleach, assuming you are running 24/7 for the 1st week.

    Unlike plaster and Diamond Brite, very little brushing will be needed. The acid wash removed the cream and exposed the aggregate. The pH changes will likely be slower to rise also since there isn't as much hydration happening anymore.

    Keep an eye out for small rust spots. Sometimes a piece of aggregate has a little iron in it, requiring a spot treatment. The result of the removal puts the iron in solution but not enough to require a sequesterant unless iron is in your fill water.

    Enjoy your pool.

    Scott
    Owner of - PoolGuyNJ LLC
    Expert Pool and Spa Repairs, Renovations, and Augmentation. Helping people decide what is the right gear for meeting their needs. Expectations Set, Expectations Met, No Surprises.

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