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Thread: FC levels

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    FC levels

    Does FC have to be higher than TC? Pool store told me to add 5 # of shock to reverse. That sounds like a lot of shock for 13k gal pool. My FC is .75 ( I know I have to raise it) and TC. Is 2.61. Just changed sand filter and cleaned salt cell. CYA is 50 CH is 410.
    13.5K IG plaster SWG sand filter

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    linen's Avatar
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    Re: FC levels

    Welcome to tfp, tbt

    FC (free chlorine) will never be higher than TC (total chlorine) unless there is testing error. TC= FC + CC
    As you raise FC, TC will also go up.

    What does your water look like?

    Pool store results are very inconsistent, but if the ones you have are right (I would not assume this) then your Combined Chlorine (CC) is higher than 0.5 ppm which indicates you need to do the SLAM process. If the pool stores cya test is correct (this is one test that pool stores are notoriously wrong at), then you SLAM level (shock level) is 20 ppm FC. Here is the pool school article for the SLAM process: http://www.troublefreepool.com/pool-...king_your_pool

    As mentioned, since pool store results are very inconsistent, so we highly recommend getting your own appropriate test kit. See this pool school article: http://www.troublefreepool.com/pool-...kit_comparison

    Speaking of pool school, there is a lot of information that will help you take charge of your pool, the link is always near the upper right of the page. This is a good article to start with: http://www.troublefreepool.com/pool-...ater_chemistry
    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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    Re: FC levels

    Water is clear and sparkly and has no odor at all
    Thanks for the info.
    13.5K IG plaster SWG sand filter

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    linen's Avatar
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    Re: FC levels

    Quote Originally Posted by tbt
    Water is clear and sparkly and has no odor at all
    Thanks for the info.
    Then I would suspect the pool store readings being inaccurate. What do you have for a test kit? Do you have a kit that can measure TC?
    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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    Re: FC levels

    No just FC. Should I test for TC before shocking?
    13.5K IG plaster SWG sand filter

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    linen's Avatar
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    Re: FC levels

    Quote Originally Posted by tbt
    No just FC. Should I test for TC before shocking?
    What kit do you have and what is your FC?
    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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    Re: FC levels

    Just using aqua check strips and pool store testing. Just order tf100
    13.5K IG plaster SWG sand filter

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    pwrstrk's Avatar
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    Re: FC levels

    You just did yourself a huge favor in getting the TF100. The strips are worthless and the pool store isn't really up to the task either. IMO.
    I would hold off on doing anything drastic until the kit comes and you can post some accurate readings.
    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: FC levels

    Thanks
    13.5K IG plaster SWG sand filter

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