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Thread: Preliminary numbers after drain/refill

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    Preliminary numbers after drain/refill

    I drained ~75% of my water and refilled it overnight. It isn't completely full yet (about 6" left), but wanted to get some preliminary numbers before I had to head to work. The pump hasn't been run yet, either, so not sure if that will affect the readings.

    pH - 8.1 (I'm not good with colors, but nearly as pink as 8.2)
    FC - 4.0
    CC - 0
    CH - 225 (down from 425)
    TA - 170
    CYA - 30 (down from 160)
    ~10K Gallon IG Plaster Pool built in 1996
    AO Smith SQ1152 1.5HP Pump
    Sta-Rite T-240BP-1 Sand Filter (62 GPM)

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    Mod Squad JVTrain's Avatar
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    Re: Preliminary numbers after drain/refill

    Looks good other than TA and pH are high but everything could certainly change after you circulate. I'd circulate for an hour and retest.
    Joel - TFP Moderator - Minnesota - **Become a TFP Supporter!** Helpful Links: ABCs of Pool Water Chemistry - SLAM Procedure - Chlorine/CYA Chart
    40x20 Pool: 32K Gallons * Vinyl * Bleach Chlorination * Hayward S270T Sand Filter * Pentair SuperFlo 1 HP * Teledyne/Laars Heater * AquaVac Tigershark * TF-100 w/ SpeedStir
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    Re: Preliminary numbers after drain/refill

    Added the recommended amount of muriatic acid and pH dropped down to 7.2.

    Will do another complete round of tests in the morning, but really happy with the numbers so far.

    Thanks for all the advice and info which have allowed me to avoid getting "pool store'd"

    On a related note, I decided to replace the O-Ring on my pump strainer basket and Leslie's had it in stock for only $25.99! I entered the part number into Amazon and got 2-day delivery for $6.99 (would have been $4.15 if I was less impatient)
    ~10K Gallon IG Plaster Pool built in 1996
    AO Smith SQ1152 1.5HP Pump
    Sta-Rite T-240BP-1 Sand Filter (62 GPM)

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    Re: Preliminary numbers after drain/refill

    You will want to bring down that TA, the ph can be brought back up after each successive MA treatment by aeration. I bet your TA only came down to 140-150

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    pwrstrk's Avatar
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    Preliminary numbers after drain/refill

    Just one thing about your TA. With each addition of acid that will lower your PH and your TA will also start to lower also.
    You don't necessarily have to target a certain TA number. Your TA will be in good spot when your PH has a slow rise. The TA may be out of range on paper, but if your PH is rather stable with a slow rise the TA is good.😎
    Jeff
    24'x54" AG Morada RTR (by wilbar) 13'500 gal. Hayward Powerflo Matrix 1hp 2 speed. Hayward Perflex EC65 DE filter.

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    Re: Preliminary numbers after drain/refill

    Have you tested your fill water? Mine was 140 out of the hose. Lowering TA usually needs to be done in more than one step.
    Pool size: 24000gal inground Vinyl-Taylor k-2006 and k-1766 test kits and-speed stir
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    Mod Squad JVTrain's Avatar
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    Re: Preliminary numbers after drain/refill

    Quote Originally Posted by Sansfear View Post

    On a related note, I decided to replace the O-Ring on my pump strainer basket and Leslie's had it in stock for only $25.99! I entered the part number into Amazon and got 2-day delivery for $6.99 (would have been $4.15 if I was less impatient)
    What a bargain! Only 300%+ mark up at Leslie's!

    Like the rest have said, as you add MA to keep the pH in range the TA will drop over time as a result until you have to add MA less frequently due to a lower TA concentration which will naturally settle where it "wants to be."
    Joel - TFP Moderator - Minnesota - **Become a TFP Supporter!** Helpful Links: ABCs of Pool Water Chemistry - SLAM Procedure - Chlorine/CYA Chart
    40x20 Pool: 32K Gallons * Vinyl * Bleach Chlorination * Hayward S270T Sand Filter * Pentair SuperFlo 1 HP * Teledyne/Laars Heater * AquaVac Tigershark * TF-100 w/ SpeedStir
    Isolated Spa - 345 Gallons

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    Re: Preliminary numbers after drain/refill

    New numbers from this morning:

    pH - 7.2
    FC - 6.0 (added bit too much bleach but wanted to give it some room to see how quickly it drops per day)
    CC - 0
    CH - 175
    TA - 140
    CYA - 30
    ~10K Gallon IG Plaster Pool built in 1996
    AO Smith SQ1152 1.5HP Pump
    Sta-Rite T-240BP-1 Sand Filter (62 GPM)

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    Re: Preliminary numbers after drain/refill

    What is your CYA goal?

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    Re: Preliminary numbers after drain/refill

    My theoretical goal was 40, so I overshot it a bit. Not sure if I should worry about it or not since it is still 'in range' (30-50).

    I plan to do one more round of lowering TA, but hopefully after that, I'll be done with major changes and can just enjoy the pool and monitor it.
    ~10K Gallon IG Plaster Pool built in 1996
    AO Smith SQ1152 1.5HP Pump
    Sta-Rite T-240BP-1 Sand Filter (62 GPM)

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    Re: Preliminary numbers after drain/refill

    Personally, I aim for CYA of 40 as that is the lowest value that you can reliably test. 30 is a guess. Also, topping off with rain or fill water will dilute CYA. If you decide to raise it, would you use powdered dichlor? That's what I like because it dissolves quickly and is easy to use.

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    pwrstrk's Avatar
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    Re: Preliminary numbers after drain/refill

    Quote Originally Posted by MarianParoo View Post
    Personally, I aim for CYA of 40 as that is the lowest value that you can reliably test. 30 is a guess. Also, topping off with rain or fill water will dilute CYA. If you decide to raise it, would you use powdered dichlor? That's what I like because it dissolves quickly and is easy to use.
    I use the TF 100 kit and I can read 30, 20 ppm of CYA with no problem.
    Jeff
    24'x54" AG Morada RTR (by wilbar) 13'500 gal. Hayward Powerflo Matrix 1hp 2 speed. Hayward Perflex EC65 DE filter.

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    Re: Preliminary numbers after drain/refill

    Numbers from this morning:

    pH - 7.5
    FC - 4.0
    CC - 0
    CH - 175
    TA - 130
    CYA - 30

    I decided to do one more round of muriatic acid, which should drop TA to 120 or so. After that, should I simply leave it alone and monitor it?

    Also, is my CH too low for a plaster pool?
    ~10K Gallon IG Plaster Pool built in 1996
    AO Smith SQ1152 1.5HP Pump
    Sta-Rite T-240BP-1 Sand Filter (62 GPM)

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    Re: Preliminary numbers after drain/refill

    CH is indeed low, raise it to 200 minimum at least. I believe 250 is recommended for Plaster.

    Just monitor TA, if it rises, beat it back again.

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