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Thread: Daily Chlorine Drop of 2-3 ppm???

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    Join Date
    Jan 2014
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    Texas
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    Daily Chlorine Drop of 2-3 ppm???

    The weather is nice here- lower 70's and my pool get full sun. My Free Chlorine level drops significantly each day. I just want to verify that this is nothing to be concerned with.

    Current Numbers

    CYA-30
    PH-7.8
    TA-175

    FC has dropped per the following each day:

    3/29/14 FC -9.8
    3/30/14 FC -7.5
    3/31/14 FC -4.5

    My plan is to add 11 oz of dichlor before days end. Any comments/suggestions??? Thanks in advance!

    Jane
    Jane in Northeast Texas

    18 x 36 Inground Vinyl Liner, 20,000 gallons, Hayward Pro Series 24" 300 lb top mount Sand Filter, Hayward Super II 1 hp pump, 1 skimmer, 2 inlets, 2 Deck Jets, Vinyl Covered Stairs, Polaris 280 Cleaner

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    Mod Squad jblizzle's Avatar
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    Re: Daily Chlorine Drop of 2-3 ppm???

    What FC are you starting at each day? The CYA sort of sets a % of the FC that is protected by the sun. As you run the FC value higher, you will lose more each day.

    Likely you will want to raise you CYA up closer to 50ppm due to your sun levels and the loss each day should drop. Use the calculator to determine how much dichlor you can use, but you have to stop when the CYA is where you want it.

    You could Perform the Overnight Chlorine Loss Test to see if there is something in the water consuming the chlorine.
    Jason, TFP Moderator
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    JasonLion's Avatar
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    Re: Daily Chlorine Drop of 2-3 ppm???

    With CYA around 30 you are losing quite a bit less chlorine than you would during the summer. I presume that is because the water is still fairly cold, which cuts down on how much chlorine is lost each day. With water in the 80s and CYA at 30 you would typically be losing 60-70% of your starting FC level each sunny day.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
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    Join Date
    Jan 2014
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    Texas
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    Re: Daily Chlorine Drop of 2-3 ppm???

    Ok Thanks! I planned on just continuing use of dichlor as it is a combination of adding additional cya and chlorine. Do you feel I should just add CYA directly to raise it faster?

    The FC rates I posted were from 8 am tests. I will look into the overnight loss as well! Thanks!

    - - - Updated - - -

    Ha! Could the chlorine loss be due to the pollen from the 5 oak trees surrounding pool?
    Jane in Northeast Texas

    18 x 36 Inground Vinyl Liner, 20,000 gallons, Hayward Pro Series 24" 300 lb top mount Sand Filter, Hayward Super II 1 hp pump, 1 skimmer, 2 inlets, 2 Deck Jets, Vinyl Covered Stairs, Polaris 280 Cleaner

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    Mod Squad jblizzle's Avatar
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    Re: Daily Chlorine Drop of 2-3 ppm???

    OH, I just realized that you are showing the actual FC reading each day and not a loss (-9.8 the first day etc.). So you are actually only losing 2-3ppm which is perfectly normal. Although as Jason said, as you get into summer the losses are going to up a lot unless the CYA is raised.

    If you have the dichlor, you can use it ... just add around 3-4ppm of FC everyday to stay above the minimum and track how much CYA you are adding. So, for you, one pound each day would add 3.3ppm FC and 3ppm CYA ... if you do that for 6 days, you would then be approaching 50ppm of CYA and need to switch to bleach.
    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
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