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Thread: Eliminating CC

  1. Back To Top    #1

    Eliminating CC

    What else should I do to eliminate the CC's in my tub?

    Initial test results 11/14 @ 2pm:
    FC: 2
    CC: 3 (calculated)
    TC: 5
    pH: 7.5
    CYA: 48
    TA: 50
    CH: 200
    Borates: 43 (calculated)
    355 gallons
    Leslie Complete Kit (Taylor chemistry)

    Shocked with 10 oz of Clorox (14 ppm) hoping to eliminate the CC's

    Follow up test results 11/15 @ 10am
    FC: 3
    CC: 1
    TC: 4
    pH: 7.5

    Not happy with the lingering CCs.
    Bumped the FC up to 5ppm with 1.5 oz of Bleach (target level)
    Added 2.75 oz (weight) of MPS as an additional oxidizer to see if I could help knock out the remaining CC.

    Comments / advice appreciated.

    Planning to soak tonight.

    Need a better chlorine test -- the drop / color block test in Leslie's kit goes up to 5 ppm and it isn't very exact. I dilute the sample 50% to get a wider range, but I think it impacts the accuracy.


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    Re: Elminating CC

    Quick follow up...

    Once I added the MPS, I turned the jets and air on high and within 15 minutes a massive sticky scum line formed around the shell at the surface. I assume that is the MPS doing its thing.

    How do you get the scum line off without adding things to the water that will mess up the balance?

  3. Back To Top    #3
    Mod Squad Bama Rambler's Avatar
    Join Date
    Jun 2009
    SouthWest Alabama

    Re: Elminating CC

    Here's what Chem Geek said about MPS reading as CC.

    Quote Originally Posted by Chem Geek
    Yes, by non-chlorine shock I mean potassium monopersulfate (MPS). Unfortunately, the MPS itself will usually register as CC in the chlorine test -- very high levels, especially soon after addition, can also show up as FC. There is a Taylor K-2042 kit to remove the MPS interference, but this isn't always reliable. The MPS may not get rid of the CC either, but it's something you could try (see what happens after the chlorine level comes back down -- that is, is the CC still there and does it still smell).
    Sounds like that may be what you're seeing.
    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

  4. Back To Top    #4

    Join Date
    Mar 2007
    San Rafael, CA USA

    Re: Elminating CC

    Measuring CC shortly after a soak will be normal as the chlorine combines with the ammonia (ane urea) from your sweat and urine. This usually breaks down within an hour or so. Were you measuring CC at the start of your soak? Also as noted above MPS will measure as CC. Are you using the Dichlor-then-bleach method?

    It isn't normal to get such as scum line so readily after using an oxidizer such as MPS. By any chance, is this a newer spa? If so, did you use Spa System Flush to initially clean out the chemicals and biofilm typically found in a new spa? With a new spa, one usually needs to replace the water sooner from that first fill; after that, it lasts much longer.
    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"

  5. Back To Top    #5

    Re: Eliminating CC

    I measured CC at least 36 hours after the last soak and 20 hours after shocking to 16 ppm chlorine.

    It is a new spa. The water and spa are 2 weeks old. Sounds like a drain and flush may be in order.

    I checked again at 5pm and:

    FC: 1
    TC: 4 (but this may be reading artificially high due to the earlier MPS shock)

    I am going to boost the FC back up to the target of 5ppm (according to the CYA/FC chart) and check the CC's again tomorrow.

  6. Back To Top    #6
    frustratedpoolmom's Avatar
    Join Date
    May 2007
    SWSuburban Chicago, IL

    Re: Eliminating CC

    I agree with Richard, since the spa is new I would drain and refill.

    Also you can order an fAS-DPD chlorine test to supplement your current kit, separately from both Taylor and TFTestkits. It's a drop-count test, not color matching - you will like it much better. Sells for about $25 but worth every penny.
    Helpful links: Pool School; CYA/Chlorine Chart
    24' round AG pool, 52" high, Raypak heater; Waterway 2 spd Pump;
    150 Sq ft. Clearwater Cartridge Filter; Former and DISSATISFIED "Pool Frog" owner
    Perfectly Clear Pool Service, Find me on Facebook!

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