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Thread: FC Loss

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    FC Loss

    Readings As of Yesterday:
    FC 5
    TA 100
    CH 260
    CYA 46
    pH 7.7

    I live in South Arkansas and we've been averaging 95-100 temp. over the last couple of weeks. I'll have anywhere from 2-6 people swimming in my pool daily. Most of the time just 2 adults and 2-3 very small children. I have very little shade. What should be my daily max FC loss assuming no other bacteria or contaminants?

    Thanks,
    Alan

    Fiberglass
    17,500 gallons
    Sand Filter

  2. Back To Top    #2
    svenpup's Avatar
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    Re: FC Loss

    This has come up here recently. The consensus is that it is hard to define since every pool is different but 2-3ppm per day seems to be acceptable.
    TFP Method Advanced Intermediate
    • 17,500 gallons - In Ground - Plaster - Hayward Swimclear 3020 Cartridge Filter - Sta-Rite Max-E-Glas Main Pump upgraded with A.O. Smith B2980 E-Plus New Centurion Two-Speed Motor - Polaris 280 Cleaner with Polaris PB4-60 Booster Pump - TightWatt2 Timer - Taylor K-2006 Test Kit - Pool Pilot Digital Nano SWCG

    Helpful Links: Pool School, BBB for Beginners, How to Shock (hint...it's a process not a product), Chlorine/CYA Chart, Jason's Pool Calculator

  3. Back To Top    #3

    Re: FC Loss

    Even with a fairly heavy swimmer load? I think I'm losing quite a bit more. Hmmmmm. And I'm not losing any overnight.

    Thanks,
    Alan

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    Re: FC Loss

    Where are you getting your test results? Your CYA reading of 46 is too precise for either the Taylor K-2006 or TF-100 test kits and makes me think your numbers might be from the pool store. If so, they could be inaccurate and you might have something else going on with your water. Otherwise, you might just want to say CYA = 40 or 50, since it can't get closer than 10 ppm.
    32x16 ft Grecian rectangular vinyl pool 8ft on deep end - 19000 gal. 18" Hayward S-240 sand filter. 250K BTU Pentair MasterTemp heater. Hayward 3/4 HP Super Pump.

  5. Back To Top    #5
    svenpup's Avatar
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    Re: FC Loss

    What is your CC? Have you done an overnight FC loss test?
    TFP Method Advanced Intermediate
    • 17,500 gallons - In Ground - Plaster - Hayward Swimclear 3020 Cartridge Filter - Sta-Rite Max-E-Glas Main Pump upgraded with A.O. Smith B2980 E-Plus New Centurion Two-Speed Motor - Polaris 280 Cleaner with Polaris PB4-60 Booster Pump - TightWatt2 Timer - Taylor K-2006 Test Kit - Pool Pilot Digital Nano SWCG

    Helpful Links: Pool School, BBB for Beginners, How to Shock (hint...it's a process not a product), Chlorine/CYA Chart, Jason's Pool Calculator

  6. Back To Top    #6

    Re: FC Loss

    I'm getting my results from the TF-100...it just looks like it's around 46 on the cylinder. I haven't done an overnight FC test in about a month. Maybe I should do that again. However, the water looks great! I'm just spending a lot of money on bleach.

    Thanks,
    Alan

  7. Back To Top    #7
    svenpup's Avatar
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    Re: FC Loss

    CC?
    Even if CC < 0.5 you may still need to shock if overnight loss > 1.0
    TFP Method Advanced Intermediate
    • 17,500 gallons - In Ground - Plaster - Hayward Swimclear 3020 Cartridge Filter - Sta-Rite Max-E-Glas Main Pump upgraded with A.O. Smith B2980 E-Plus New Centurion Two-Speed Motor - Polaris 280 Cleaner with Polaris PB4-60 Booster Pump - TightWatt2 Timer - Taylor K-2006 Test Kit - Pool Pilot Digital Nano SWCG

    Helpful Links: Pool School, BBB for Beginners, How to Shock (hint...it's a process not a product), Chlorine/CYA Chart, Jason's Pool Calculator

  8. Back To Top    #8

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    Re: FC Loss

    Each person-hour of people (with some swimming) in your 17,500 gallon pool would have a chlorine demand of around 0.06 ppm, though that assumes no peeing in the pool. If the children (or adults) pee, then that can shoot your chlorine demand way up. One cup of urine in your pool would create a chlorine demand of around 0.4 ppm FC.
    16,000 gallon outdoor in-ground 16'x32' plaster pool; Pentair Intelliflo VF pump; Pentair IntelliTouch i9+3s control system; Jandy CL-340 square foot cartridge filter
    12 Fafco solar panels; Purex Triton PowerMax 250 natural gas heater (200,000 BTU/hr output); automatic electric pool safety cover; 4-wheel pressure-side "The Pool Cleaner"

  9. Back To Top    #9
    svenpup's Avatar
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    Re: FC Loss

    Quote Originally Posted by chem geek
    ...One cup of urine in your pool would create a chlorine demand of around 0.4 ppm FC.
    Richard, there is no limit to your knowledge.
    TFP Method Advanced Intermediate
    • 17,500 gallons - In Ground - Plaster - Hayward Swimclear 3020 Cartridge Filter - Sta-Rite Max-E-Glas Main Pump upgraded with A.O. Smith B2980 E-Plus New Centurion Two-Speed Motor - Polaris 280 Cleaner with Polaris PB4-60 Booster Pump - TightWatt2 Timer - Taylor K-2006 Test Kit - Pool Pilot Digital Nano SWCG

    Helpful Links: Pool School, BBB for Beginners, How to Shock (hint...it's a process not a product), Chlorine/CYA Chart, Jason's Pool Calculator

  10. Back To Top    #10
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    Re: FC Loss

    Quote Originally Posted by svenpup
    Quote Originally Posted by chem geek
    ...One cup of urine in your pool would create a chlorine demand of around 0.4 ppm FC.
    Richard, there is no limit to your knowledge.
    No kidding! Richard tracked an FC loss from his own pool a couple years ago...........
    and it was/is one of the most entertaining threads on TFP

    Richard may decide to link us up
    TFP Moderator TF100 Test Kit TF100 TestKit YouTube Channel PoolMath
    You're done SLAMing when:
    1)You lose 1ppm or less FC overnight, & 2)You have .5ppm CC's or less, & 3)your water is clear.

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    ssa's Avatar
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    Re: FC Loss

    Quote Originally Posted by Butterfly
    No kidding! Richard tracked an FC loss from his own pool a couple years ago...........
    and it was/is one of the most entertaining threads on TFP

    Richard may decide to link us up
    I want to see that.
    15x32 vinyl, IG,17K gal, DE filter, Hayward 3/4 HP pump, Hayward Ultra Vac, Solar cover with reel
    SportCount LapCounter, FINIS SwiMP3.1G
    Enjoying my pool thanks to TFP.com

  12. Back To Top    #12
    svenpup's Avatar
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    Re: FC Loss

    Based on this data I could come up with an equation:
    • You enter baseline daily FC demand, FC demand for a pool party day, number of swimmer hours, and solve for cups of pee.


    Maybe we could get Jason to add it to the Pool Calculator.
    TFP Method Advanced Intermediate
    • 17,500 gallons - In Ground - Plaster - Hayward Swimclear 3020 Cartridge Filter - Sta-Rite Max-E-Glas Main Pump upgraded with A.O. Smith B2980 E-Plus New Centurion Two-Speed Motor - Polaris 280 Cleaner with Polaris PB4-60 Booster Pump - TightWatt2 Timer - Taylor K-2006 Test Kit - Pool Pilot Digital Nano SWCG

    Helpful Links: Pool School, BBB for Beginners, How to Shock (hint...it's a process not a product), Chlorine/CYA Chart, Jason's Pool Calculator

  13. Back To Top    #13

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    Re: FC Loss

    The thread you are looking for is Unusual Chlorine Demand -- Peeing in the Pool. Yes, with your trusty FAS-DPD chlorine test kit and knowing the "normal" chlorine demand in your pool without the "extra" bather load, you can indeed detect when someone has been peeing in the pool. Whether you want to actually disclose/question a certain person about your suspicions is another matter.
    16,000 gallon outdoor in-ground 16'x32' plaster pool; Pentair Intelliflo VF pump; Pentair IntelliTouch i9+3s control system; Jandy CL-340 square foot cartridge filter
    12 Fafco solar panels; Purex Triton PowerMax 250 natural gas heater (200,000 BTU/hr output); automatic electric pool safety cover; 4-wheel pressure-side "The Pool Cleaner"

  14. Back To Top    #14
    svenpup's Avatar
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    Re: FC Loss

    When I checked my pools pH it was all pee, no H.
    TFP Method Advanced Intermediate
    • 17,500 gallons - In Ground - Plaster - Hayward Swimclear 3020 Cartridge Filter - Sta-Rite Max-E-Glas Main Pump upgraded with A.O. Smith B2980 E-Plus New Centurion Two-Speed Motor - Polaris 280 Cleaner with Polaris PB4-60 Booster Pump - TightWatt2 Timer - Taylor K-2006 Test Kit - Pool Pilot Digital Nano SWCG

    Helpful Links: Pool School, BBB for Beginners, How to Shock (hint...it's a process not a product), Chlorine/CYA Chart, Jason's Pool Calculator

  15. Back To Top    #15

    Re: FC Loss

    My CC is .5 or less and I performed an overnight FC loss test last night. I had a reading of 8 at 9:30pm and a reading of 6.5 at 6:30 this morning. It was daylight at around 6:00, but the sun didn't rise near the pool area until around 7:00ish. Should I have tested before daylight to get the most accurate reading, or should I be convinced that something else is in the pool if I lost 1.5 ppm between 9:30 and 6:30?

    Thanks,
    Alan

  16. Back To Top    #16

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    Re: FC Loss

    You need to get the morning test before the sun is on the pool, with 1.5 ppm seems like a lot to lose with that little bit of sun. I'd shock it again tonight and get an overnight FC loss test without any sun on the pool (evening or morning) and see what it looks like. You've probably got a few more days of shocking to do.
    32x16 ft Grecian rectangular vinyl pool 8ft on deep end - 19000 gal. 18" Hayward S-240 sand filter. 250K BTU Pentair MasterTemp heater. Hayward 3/4 HP Super Pump.

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