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Thread: CYA takes a while to show on test?

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    CYA takes a while to show on test?

    Okay, can someone explain this to me? I keep hearing that CYA takes a while to show up on the test. What does that mean, exactly? If the granules have dissolved, why wouldn't the impact show on the test as soon as it's been circulated? Are they simply referring to the fact that it takes a while for the CYA to dissolve, or is there some other interaction that takes time to occur before it's "active" CYA?

    I just don't understand how CYA can be in the water in a specific concentration, yet not show up on a test for several days.
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    Re: CYA takes a while to show on test?

    I'm not the Chemgeek, so hopefully he will chime in. From what I understand, CYA is one of the hardest to measure accurately and yes, it takes a while for it to register. Even if you can't see the granuales, it's still dissolving.
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    Re: CYA takes a while to show on test?

    CYA does take upto a week to fully dissolve and activate, I don't know why but it does.

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    Re: CYA takes a while to show on test?

    so even after dissolving out of a sock in the skimmer, we should wait about a week to take the measurement?

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    UnderWaterVanya's Avatar
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    Re: CYA takes a while to show on test?

    Quote Originally Posted by scottj21
    so even after dissolving out of a sock in the skimmer, we should wait about a week to take the measurement?
    Scott, typically it is not recommended to put CYA in skimmer. However - yes the fact that the CYA appears gone does not mean it will show up on the tests.

    Dichlor I think adds CYA more quickly but I don't understand why.


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    Re: CYA takes a while to show on test?

    CYA sometimes shows up soon after being added to the water and other times it takes up to a week to fully register in the test. To be safe, it is best to wait a week after adding a dose before adding another dose of CYA to reach your target if more is needed.
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    Re: CYA takes a while to show on test?

    Quote Originally Posted by ping
    CYA sometimes shows up soon after being added to the water and other times it takes up to a week to fully register in the test. To be safe, it is best to wait a week after adding a dose before adding another dose of CYA to reach your target if more is needed.
    This is the bottom line ^

    My pool has it in the water about a day and a half later. Yours may be different. Since removing CYA can be difficult, it is better to err on the side of caution to make sure you aren't overshooting.
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    Re: CYA takes a while to show on test?

    thanks

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    Re: CYA takes a while to show on test?

    Quote Originally Posted by ping
    CYA sometimes shows up soon after being added to the water and other times it takes up to a week to fully register in the test. To be safe, it is best to wait a week after adding a dose before adding another dose of CYA to reach your target if more is needed.
    Great point ^^^^.
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    Re: CYA takes a while to show on test?

    I'm waiting patiently. I'll check it once a day and see what shows up when. I should be pushing 20 by now, thanks to some early use of trichlor, a treatment I did last night, and rubbing a trichlor tablet on black stains to see if they're black algae. I couldn't tell much difference after the try, myself, so the results were inconclusive.
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    Re: CYA takes a while to show on test?

    Quote Originally Posted by SebringDon
    I'm waiting patiently. I'll check it once a day and see what shows up when. I should be pushing 20 by now, thanks to some early use of trichlor, a treatment I did last night, and rubbing a trichlor tablet on black stains to see if they're black algae. I couldn't tell much difference after the try, myself, so the results were inconclusive.
    Which test kit do you have? If you have the TF100 then go for it but I'd recommend only testing when you have added another 10-15ppm because there are limited tests maybe 16?. The K2006 has fewer CYA tests worth of reagent - I think only 4?
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    Re: CYA takes a while to show on test?

    Might want to space out the CYA tests to more than once per day, it uses a lot of regents and I am not sure that daily tests will give you much useful/actionable information.
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    Re: CYA takes a while to show on test?

    When I add CYA to my pool, it shows up as soon as it is dissolved (i.e. the next day), but that's in a T-shirt in the skimmer. If one adds CYA directly into the skimmer so that it gets caught in the filter, which is what many CYA directions say to do, then it can take longer to dissolve since the water flow rate in some filters can be very slow, especially for oversized filters.

    If one dissolves the CYA in some material that lets small CYA particles through, then those particles may take longer to dissolve if they settle to the bottom of the pool. So it's safer to just say wait before measuring to be sure.
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    UnderWaterVanya's Avatar
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    Re: CYA takes a while to show on test?

    Quote Originally Posted by chem geek
    When I add CYA to my pool, it shows up as soon as it is dissolved (i.e. the next day), but that's in a T-shirt in the skimmer. If one adds CYA directly into the skimmer so that it gets caught in the filter, which is what many CYA directions say to do, then it can take longer to dissolve since the water flow rate in some filters can be very slow, especially for oversized filters.

    If one dissolves the CYA in some material that lets small CYA particles through, then those particles may take longer to dissolve if they settle to the bottom of the pool. So it's safer to just say wait before measuring to be sure.
    That's pretty helpful. Do you see any lag on dichlor added CYA?


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    Re: CYA takes a while to show on test?

    When I used Dichlor one time to raise both FC and CYA, the amount wasn't large enough to know that the CYA was definitively higher, but given how fast it dissolves I'd say that it should probably show up within a day. Remember, however, that one must have reasonable circulation in the pool so it's still best to add the Dichlor slowly over a return flow to mix it rather than dump it somewhere in the pool without good circulation.

    We've had reports about "bad CYA" on this forum where using a different brand fixed the problem. Apparently some manufacturers in China are pulling the same stunts of not selling what they claim (remember the melamine scandal affecting pet food) and some importers here have been duped.
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