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Thread: Free and total chlorine issues

  1. Back To Top    #1

    Join Date
    May 2007
    Alberta, Canada

    Free and total chlorine issues

    I am using a Color Q photometric test kit by LaMotte. Which aside from a couple of issues, I love.
    My problem is that no matter what I seem to do I cannot get my free and total chlorine numbers in line.
    They are always consistently more than .20 apart, which because I have a semi public pool concerns me.
    I don't think it is the test because I have used my DPD tests and get very similar results. I've also had my water tested at a pool place.
    And just to prove a little knowledge is a dangerous thing, I just took my first level pool operator course and I now feel more confused than ever.
    My question is how do I go about getting these numbers closer together?
    I have to submit water samples once a week to the health department and have already got two unsatisfactory results, something I don't want to repeat.
    I have a 100,000 litre vinyl in ground pool. We have no less than 10 to 30 people in the pool at all times on the weekend and very little bather load during the week. (We are a campground)
    Last readings
    PH 7.3
    Alk 132
    Free Chl 2.00
    Total Chl 2.71
    Hardness 350
    Cyn Acid 100 (yes, I know it's high, that was one problem with the Color Q, inaccurate for Cyn acid, so I added)
    Phos 1000
    TDS 967
    I use Trichlor pucks in our Hayward feeder and calcium hypo for shock. I also have been using Pool Perfect.
    I notice that my pool gets very cloudy by Saturday night and then takes a couple of days to clear. Is there any way to avoid that? I know it's the heavy bather load and all the various things they put in the water but there must be a way to keep it clearer.

    We are installing sensor and auto feeds for Chlorine and Ph soon but in the mean time I'd like to get on top of this.
    Thanks in advance
    100,000 liter IG vinyl liner
    Rolachem Chlorine & Muratic acid Auto feeders/Pool Perfect Auto feeder
    Pentair 30" filter (Tagelus) Sand filter/Centruion switchless pump 1.5/.25 HP

  2. Back To Top    #2

    Join Date
    Mar 2007
    Welcome to the forum deena, The one thing that sticks out about your numbers is, your CL is not high enough for a cya of 100, the higher your cya is the higher you need to run your CL. Ben from the forum from which all this started has a chart that tells you what numbers to run with cya numbers:

    Ben Powell's 'best guess' FC/Stabilizer table for algae free operation of OUTDOOR pools
    -- as of July 2003 --

    CYA-Stabilizer . . . . . . Min. FC . . . . Max FC . . . 'Shock' FC
    => 0 ppm . . . . . . . 1 ppm . . . . . 3 ppm . . . . 10 ppm
    => 10 - 20 ppm . . . . 2 ppm . . . . . 5 ppm . . . . 12 ppm
    => 30 - 50 ppm . . . . 3 ppm . . . . . 6 ppm . . . . 15 ppm
    => 60 - 90 ppm . . . . 5 ppm . . . . . 10 ppm . . .. 20 ppm
    => 100 - 200 ppm . . . 8 ppm . . . . . 15 ppm . . .. 25 ppm
    credit Pool Forum/Ben Powell

    Hope this helps and I would say someone else will probably chime that is smarter then me and possibly add to this
    27' Round AG, 17,200 gallons, sand filter

  3. Back To Top    #3
    JasonLion's Avatar
    Join Date
    May 2007
    Silver Spring, MD
    You can get rid of CC by shocking the pool, however if you don't keep your FC level higher you will just get CC again. Sunlight and higher chlorine levels will keep the CC away. If your pool is indoors things are more complex. You should double check your health department rules to make sure a FC of 8-15 is allowed. Not all jurisdictions have fully taken into account how CYA works. If they won't let you keep your chlorine level high enough you will need to replace water to get your CYA level down.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  4. Back To Top    #4

    Join Date
    May 2007
    Alberta, Canada

    Thanks and update

    Thanks for the info.
    I shocked the pool and was able to get 0 CC.
    I will be checking with my health department about the high chlorine levels. I have a feeling they won't allow it but it's worth asking. If not, then I will drain some off.
    In a 100,000 litre CYA at 100. How much will I have to drain off? Anyone have any ideas on that?
    (By the way, I fired the pool guy who got my CYA up that high. I had asked him to vacuum the pool and test it but not add anything and when I came back he had added 10kg of shock and at least a kg of Cyanuric acid.)I've been trying to fix those errors ever since.
    Todays readings
    FC 9.63
    TC 9.63
    PH 7.5
    Alk 131
    CH 400
    100,000 liter IG vinyl liner
    Rolachem Chlorine & Muratic acid Auto feeders/Pool Perfect Auto feeder
    Pentair 30" filter (Tagelus) Sand filter/Centruion switchless pump 1.5/.25 HP

  5. Back To Top    #5

    Join Date
    Apr 2007
    You would need to drain about half to get it to 50.

    14,000 gallon, in ground, plaster, free form, play pool.
    Sta-Rite Max-E-Glass with a 1.5 hp Emerson motor
    WaterCo Micron High Rate sand filter S750 490 lb, 4883 sq ft - using ZeoBest
    In floor Polaris cleaning system
    Blue Diamond robot for those after storm days when I can't wait overnight for the in floor to clean it.

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