Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 9 of 9

Thread: What FC Level is Swimming OK

  1. Back To Top    #1

    What FC Level is Swimming OK

    What is the highest a FC level can be before you don't allow people in the pool ?
    18X40, 27K gal, vinyl, 1 1/2 HP Hayward, Hayward Sand filter

  2. Back To Top    #2

    Re: What FC Level is Swimming OK

    You need to know the CYA level, then use the Chlorine/CYA chart to find the shock level. Safe to swim below shock level.

    When we were working on a friend's pool that had black algae (BA) and it was somewhere near shock level, my husband went in with mask and snorkel to attack some pits that had algae. After maybe 10 minutes his lips and nose were slightly burning. I sat at the edge and scrubbed with a pole and SS brush and managed to get wet when the FC was closer to mustard algae shock levels, my bikini parts were unhappy for days.
    23,000 gallon in ground pool with rock waterfall and spillover spa, Aqualink control system, Polaris 380 cleaner, Purex Triton Clean&Clear Plus cartridge filter. Located in The Woodlands, Texas.

    Pool owner since Nov 2008, Trouble Free since April 2009. Happy to help when I can.

  3. Back To Top    #3
    Mod Squad jblizzle's Avatar
    Join Date
    May 2010
    Location
    Tucson, AZ
    Posts
    37,389

    Re: What FC Level is Swimming OK

    from what I have read, I did not think shock level would have that harsh an effect ... unless the cya was off or you were way above shock level. Was the pH in range?

    In any case, I agree we need to know the CYA level to give our general recommendation ... which I was under the impression was conservative.

    Posted from my Droid with Tapatalk ... sorry if my response is short
    Jason, TFP Moderator
    18k IG pebblesheen pool, Hayward ProLogic P4 w/ T-15 SWG, Pentair 1HP 2-speed Superflo, Hayward 6020 DE filter
    500 sqft Heliocol solar panels, ThePoolCleaner, TF-100 test kit w/ SpeedStir
    Pool School + Test Kit + PoolMath = A TROUBLE FREE POOL
    If you found TFP helpful and we saved you money ... Become a TFP Supporter!

  4. Back To Top    #4

    Re: What FC Level is Swimming OK

    Hi,

    If the CYA was 45 and the FC was 24 would it be ok to have people in the pool ?
    18X40, 27K gal, vinyl, 1 1/2 HP Hayward, Hayward Sand filter

  5. Back To Top    #5
    Mod Squad jblizzle's Avatar
    Join Date
    May 2010
    Location
    Tucson, AZ
    Posts
    37,389

    Re: What FC Level is Swimming OK

    How does the water look? How/why did the FC get so high?

    Shock level for CYA of 45 ppm is about 18ppm ... so I would have to recommend against swimming at 24ppm. If you stop adding chlorine, it should be below 18ppm in 1-2 days.
    Jason, TFP Moderator
    18k IG pebblesheen pool, Hayward ProLogic P4 w/ T-15 SWG, Pentair 1HP 2-speed Superflo, Hayward 6020 DE filter
    500 sqft Heliocol solar panels, ThePoolCleaner, TF-100 test kit w/ SpeedStir
    Pool School + Test Kit + PoolMath = A TROUBLE FREE POOL
    If you found TFP helpful and we saved you money ... Become a TFP Supporter!

  6. Back To Top    #6

    Join Date
    Mar 2007
    Location
    San Rafael, CA USA
    Posts
    12,082

    Re: What FC Level is Swimming OK

    Quote Originally Posted by anonapersona
    When we were working on a friend's pool that had black algae (BA) and it was somewhere near shock level, my husband went in with mask and snorkel to attack some pits that had algae. After maybe 10 minutes his lips and nose were slightly burning. I sat at the edge and scrubbed with a pole and SS brush and managed to get wet when the FC was closer to mustard algae shock levels, my bikini parts were unhappy for days.
    Were these problems noticed after you both got out of the water? While in the water, the active chlorine level wouldn't have been any higher than a commercial/public pool with no CYA, such as most indoor pools. However, outside the water, the chlorine would have lasted longer and when the water evaporated may have caused some irritation from the resulting chlorinated CYA products that remained (similar to Dichlor). Rinsing off immediately after getting out should hopefully prevent this sort of situation.
    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"

  7. Back To Top    #7

    Join Date
    Jun 2012
    Location
    Minneapolis, MN
    Posts
    16

    Re: What FC Level is Swimming OK

    Our city states FC levels must be at 10ppm or less for swimming, but I don't know that there's really a "safe" maximum. Restaurants typically sanitize plates and other equipment in water with 100ppm of chlorine, so I think you have to be pretty far up for it to be unsafe. Remember that irritating or uncomfortable may be different than unsafe.
    27,000-gallon plaster IG, sand filter, flow rate 80-90.

  8. Back To Top    #8
    Mod Squad jblizzle's Avatar
    Join Date
    May 2010
    Location
    Tucson, AZ
    Posts
    37,389

    Re: What FC Level is Swimming OK

    Quote Originally Posted by csever82
    Our city states FC levels must be at 10ppm or less for swimming, but I don't know that there's really a "safe" maximum. Restaurants typically sanitize plates and other equipment in water with 100ppm of chlorine, so I think you have to be pretty far up for it to be unsafe. Remember that irritating or uncomfortable may be different than unsafe.
    And that just points out the governments ignorance of the CYA/FC relationship. A FC of 10ppm with no CYA is very harsh; while a FC of 10ppm at higher CYA levels would have less active chlorine than a FC of 2ppm with no CYA.
    Jason, TFP Moderator
    18k IG pebblesheen pool, Hayward ProLogic P4 w/ T-15 SWG, Pentair 1HP 2-speed Superflo, Hayward 6020 DE filter
    500 sqft Heliocol solar panels, ThePoolCleaner, TF-100 test kit w/ SpeedStir
    Pool School + Test Kit + PoolMath = A TROUBLE FREE POOL
    If you found TFP helpful and we saved you money ... Become a TFP Supporter!

  9. Back To Top    #9

    Join Date
    Jun 2012
    Location
    Minneapolis, MN
    Posts
    16

    Re: What FC Level is Swimming OK

    Quote Originally Posted by jblizzle
    Quote Originally Posted by csever82
    Our city states FC levels must be at 10ppm or less for swimming, but I don't know that there's really a "safe" maximum. Restaurants typically sanitize plates and other equipment in water with 100ppm of chlorine, so I think you have to be pretty far up for it to be unsafe. Remember that irritating or uncomfortable may be different than unsafe.
    And that just points out the governments ignorance of the CYA/FC relationship. A FC of 10ppm with no CYA is very harsh; while a FC of 10ppm at higher CYA levels would have less active chlorine that a FC of 2ppm with no CYA.
    Somehow I meant to add a similar statement to my post and forgot to. That's kind of what I meant to say - that FC level is relative to a certain degree.
    27,000-gallon plaster IG, sand filter, flow rate 80-90.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •