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Thread: Chlorinating Pool up to 'shock' level initiially

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    Chlorinating Pool up to 'shock' level initiially

    In the sticky it says the following when initially chlorinating the pool.

    "Add enough chlorine to bring the pool up to shock level. Wait half an hour. Then test the FC level, and add enough chlorine to bring the FC back up to shock level. Repeat this cycle: test, add chlorine, wait, as many times as you have time for, or until the FC level remains nearly at shock level after a one hour wait.
    "


    I went to the pool calculator and put in goal FC of 10 for shock level. Tells me to put in 96 oz of bleach. My AK is about 100, PH is 7.5 and my CYA is at best a 10. I've put in 96oz of Bleach but the FC level only gets to about 1. Am i mistaken in thinking the PoolCalc is telling me that I should be at FC=10 once I put in 96 oz of Bleach ?

    My pool is really clear and not cloudy so I was thinking it wouldn't take too much bleach to see a shock level. But so far I've put in 300oz of Bleach (100oz ever 30 minutes for 1.5 hours) and the FC remains at best at a 1. Is it normal to burn through a ton of bleach in the initial process to even get to shock level (5 gallons, 10 gallons ? etc.)
    sbelgrave @ Westminster, MD
    Size : 16 x 32 x 4
    Volume : 12,000 Gallons
    Material :Vinyl
    Water Type : Non-Saltwater

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    Mod Squad JohnT's Avatar
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    The 96oz is the jug size. For your pool, it tells me that you need 207oz to go to 10ppm.
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    JasonLion's Avatar
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    When you first open the pool it is fairly common for there to be an initial very high chlorine demand even if the water is completely clear. This is particularly true when the CYA level dropped over the winter. Just how much chlorine that will be for your pool is difficult to guess but 3-10 gallons isn't at all surprising.
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    Wow, glad to hear that. Maybe I should stock up on some more chlorine tomorrow before I embark on this fully. I think I have about 6 (6%) gallons and 3 (12.5 %) gallons left of bleach.
    sbelgrave @ Westminster, MD
    Size : 16 x 32 x 4
    Volume : 12,000 Gallons
    Material :Vinyl
    Water Type : Non-Saltwater

  5. Back To Top    #5
    Quote Originally Posted by JohnT
    The 96oz is the jug size. For your pool, it tells me that you need 207oz to go to 10ppm.
    So sorry. I realized I didn't type that i was using 12.5% chlorine so I'm sure thats why the calc says 207oz instead of the 96oz I was referring to. My mistake.
    sbelgrave @ Westminster, MD
    Size : 16 x 32 x 4
    Volume : 12,000 Gallons
    Material :Vinyl
    Water Type : Non-Saltwater

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