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Thread: CYA test

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    CYA test

    Like others when testing for CYA the black dot never disappears! What is the concern over the test results not actually being zero? I don't understand.
    Cement pool 50,000 gals. nine foot deep at one end
    kidney shaped. Large DE filter and pump.

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    Mod Squad JohnT's Avatar
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    If the black dot never disappears, you have little to no CYA. This means your chlorine will drop pretty rapidly when the water is exposed to sunlight.
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    20K Gallon 20X36 Vinyl Inground
    Hayward S244T Sand Filter with 1HP Whisperflo Pump. Liquidator C-201 and Solar Heat

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    Guest
    You don't want your CYA to be zero. If you have an outdoor pool and you are manually chorinating (as oppsoed to using s SWG) then you want your CYA to be 30-50 ppm.

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    CYA test

    I read somewhere that the pool CYA might not really be at zero; even though even though it indicates zero. Concern?
    Cement pool 50,000 gals. nine foot deep at one end
    kidney shaped. Large DE filter and pump.

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    Mod Squad JohnT's Avatar
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    I don't know how it could unless you've just added CYA and it hasn't dissolved yet. A little cloudiness to the water can throw the reading off by 20 or 30ppm to the high side, but I don't know any way the test could read it too low.
    TFP Moderator
    20K Gallon 20X36 Vinyl Inground
    Hayward S244T Sand Filter with 1HP Whisperflo Pump. Liquidator C-201 and Solar Heat

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    JasonLion's Avatar
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    CYA can sometimes read zero when it is at 20 or below. If it reads zero, you don't have very much CYA, though you may have more than zero.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
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