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Thread: Question on Shock

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    Join Date
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    Question on Shock

    My pool has not been very clear. Everyday there is some algea (dead) on the bottom of the pool that seems to be like dirt. My levels seem to be ok. Do I still need to shock?

    Here are my levels:

    FC 3.5
    CC 0
    PH 7.2
    TA 110
    CYA 40

    Thanks!
    24" Round Above Ground 52" high
    Jacuzzi CFR 100 Platinum Filter

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    Re: Question on Shock

    If you can see algae, you need to shock even if your test results are good. You're pretty close to the minimum FC for your CYA, so it's quite plausible that you've dipped below at some point and let a bloom take hold.
    20k gallon IGP
    Plaster over gunite
    3/4 hp Hayward pump
    Purex Triton DE filter
    TF100 test kit w/ speedstir

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    Re: Question on Shock

    Quote Originally Posted by Beamup
    If you can see algae, you need to shock even if your test results are good. You're pretty close to the minimum FC for your CYA, so it's quite plausible that you've dipped below at some point and let a bloom take hold.
    I have dipped below a couple times, so I think that must be what happend. Shock level is 16 for my CYA correct?
    24" Round Above Ground 52" high
    Jacuzzi CFR 100 Platinum Filter

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    Re: Question on Shock

    Yep, that's what the Chlorine/CYA Chart says.
    20k gallon IGP
    Plaster over gunite
    3/4 hp Hayward pump
    Purex Triton DE filter
    TF100 test kit w/ speedstir

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    Mod Squad Bama Rambler's Avatar
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    Re: Question on Shock

    I'd suggest running the OCLT. That would be the definitive answer to whether you have something that you need to shock for.
    Dave J. TFP Moderator
    24' x 52" Round AGP. 2hp/¼hp SPL Power-Flo 2-speed pump. 200sqft Waterway Cartridge Filter. 45MHP2(3GPD) Stenner Peristaltic Pump
    Pool School ----- Pool Math ----- TF-Test Kit

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    Re: Question on Shock

    Quote Originally Posted by Bama Rambler
    I'd suggest running the OCLT. That would be the definitive answer to whether you have something that you need to shock for.
    Last night I took the pool to shock level. When I checked this morning, it dropped to 11 so I brought it back up to shock level again. I will check tonight and see what the level is. I think it is getting better though, becuase the water is getting more clear.
    24" Round Above Ground 52" high
    Jacuzzi CFR 100 Platinum Filter

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    Re: Question on Shock

    Last night I took the pool to shock level. When I checked this morning, it dropped to 11 so I brought it back up to shock level again.
    Well, if you added the shock value chlorine after the sun was off the pool, you performed the OCLT and lost 5ppm.

    Since the max allowed reduction is 1.0, your 5ppm drop suggests excessive organics in your pool (algae) and the very real need to shock. Be sure to get your FC right back up to 16 and keep it there until you meet these targets.

    1. Your water is crystal clear.
    2. You lose less than 1.0 FC during the OCLT.
    3. Your CC's test is .5 or less
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

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