Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 3 of 3

Thread: What killed my chlorine?

  1. Back To Top    #1
    thehowheels's Avatar
    Join Date
    Apr 2013
    Location
    SoCal
    Posts
    120

    What killed my chlorine?

    My average FC loss during the day is about 2 PPM, however on Sunday I measured the pool in the afternoon and found ZERO FC. There were only two factors that I had changed since Saturday that may have contributed to it:

    * Added 12 lbs calcium carbonate dihydrate to get CH from 200 to 300
    * Accidentally left the heater on Spa mode (104 degrees) after using the hot tub on Saturday night. I switched the valves to spillover mode, so the heater was heating the entire pool.

    My pump (and thus the heater) had only been running for 2.5 hours when I caught the issue (both the lack of FC and the heater running). Was that enough to zap out my chlorine?

    Full set of numbers, which I took yesterday:

    FC: 5
    CC: 0
    pH: 7.5
    TA: 80
    CH: 300
    CYA: 40

    Since Sunday, it appears I'm back to the usual 2 PPM FC drop per day, even though it's been raining. 0 FC loss overnight.
    Matt
    9k gallon, plaster, IG. Raised spa w/ spillover into pool. AO Smith Century Centurion / Purex Triton WisperFlo 0.5 HP, Hayward 1.5 HP (spa), Polaris 1-516-01 1.5 HP (blower). Hayward DE3620 36 ft2 72 GPM DE Filter, Polaris 145 cleaner. Pool built ~1980.
    Trouble-free, BBB since: April 25, 2013

  2. Back To Top    #2
    harleysilo's Avatar
    Join Date
    Mar 2012
    Location
    North Georgia
    Posts
    1,924

    Re: What killed my chlorine?

    Did you add chlorine to your spa after you were finished Sat. night?
    18'x43' Sport Pool
    19,000 Gallons Vinyl Liner 3'-3.5'-4'
    SWCG and D.E. Filter
    Test Kits - Pool Calculator - Chlorine/CYA Chart - Pool School

    Secret Weapon for Pool Chemistry Testing

  3. Back To Top    #3
    thehowheels's Avatar
    Join Date
    Apr 2013
    Location
    SoCal
    Posts
    120

    Re: What killed my chlorine?

    Quote Originally Posted by harleysilo
    Did you add chlorine to your spa after you were finished Sat. night?
    No. I added chlorine about 1 hour before, but not after. We used the spa for maybe 2 hours total.
    Matt
    9k gallon, plaster, IG. Raised spa w/ spillover into pool. AO Smith Century Centurion / Purex Triton WisperFlo 0.5 HP, Hayward 1.5 HP (spa), Polaris 1-516-01 1.5 HP (blower). Hayward DE3620 36 ft2 72 GPM DE Filter, Polaris 145 cleaner. Pool built ~1980.
    Trouble-free, BBB since: April 25, 2013

Posting Permissions

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