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Thread: Spa confusion

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    Spa confusion

    Spa 450 gallons, 99 degrees
    CC 10 (just shocked)
    PH 7.8
    TA 50
    CH 40
    CYA not sure, ran out of test regent, ordered more....I changed the water 10 days ago, so not much if any.
    Borates 50 (boric acid)

    I am confused about the TA. Sometimes I read that it should be 50, others 100. What do you say?
    Is a calcium hardness of 40 ok for a spa?
    I ordered plenty of CYA test regent, what reading will allow me to switch to bleach? Fresh fill 10 days ago, I am using sodium dichloro s-triazinetrione as a sanitizer per bathing load and sodium dichlor once a week for shock.

    ptblues2

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    linen's Avatar
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    Re: Spa confusion

    Quote Originally Posted by ptblues2
    CC 10 (just shocked)
    Do you mean FC of 10? What is the FC and CC?

    Quote Originally Posted by ptblues2
    I am confused about the TA. Sometimes I read that it should be 50, others 100. What do you say?
    With your 50 ppm borates, you want TA close to 50 ppm since your ph will naturally rise due to the aeration of your spa.

    Quote Originally Posted by ptblues2
    Is a calcium hardness of 40 ok for a spa?
    What surface is your spa made of? Generally, lower is better unless you have a plaster surface. Low calcium can help prevent you heater from getting scale. Sometimes people with low CH experience excessive foaming...if that happens you can raise the CH up to 100-150 ppm.

    Quote Originally Posted by ptblues2
    I ordered plenty of CYA test regent, what reading will allow me to switch to bleach? Fresh fill 10 days ago, I am using sodium dichloro s-triazinetrione as a sanitizer per bathing load and sodium dichlor once a week for shock.
    Do you know how much dichlor you have used? That is the best way to keep track of when to switch. Once you get to 30 ppm cya, then switch to bleach...this is ~ 3.5 oz (by weight) of dichlor for your 450 gallon tub, or about 6.5 tablespoons of dichlor.
    TFP Expert who uses Pool School and my TF100 test kit along with PoolMath for my: Round 11K gallon AGP with deep end, 20" sand filter, Matrix 1hp 2spd, 6 2ftX20ft solar panels (and solar cover!), Intex SWCG (copper bars disconnected) and a Rubadub hot tub (chlorine). The SLAM process is not finished until: 1. CC < 0.5 ppm, 2. An OCLT < 1.0 ppm and, 3. The water is crystal clear.

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