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Thread: Do I need to shock or not?

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    Do I need to shock or not?

    In ground pool
    All parameters are good, with TA about 80, CYA 40-60 (can't figure out the best way to test it)
    PH tends to rise to a little over 7.8 and I bring it down every few weeks.
    I use liquid 12.5%, about 2 128oz bottles in 4-5 days which keeps FC around 3-5.


    It's been too hot lately and I forgot to add chlorine. When I checked I had about 0.5-1 and a few spots with green dust that may be algae (maybe 5 palm size spots on walls in shaded area). The green spots come off right away when brushing or even touching with your hand (dust or algae?).

    I remember reading somewhere that you need to shock if your chlorine level got below the minimum according to FC\CYA chart. I tried to find that post, but the new SLAM page mentions a need to shock when chlorine level at 0 and doesn't mention minimum

    I added PH down and brushed my walls. Everything looks good. Do I need to shock in this case?

    Thanks.

    Edit:
    CC is 0.5 or lower;
    water is clear.
    23k in-ground plaster. Cartridge filter Hayward 450 or 550. Hayward 2ph pump.
    liquid chlorine, tablets occasionally when out of liquid and cya allows it. ph down.
    stabilizer (Had no cya last two openings, but never before that)
    no other chemicals used in years
    TF100.

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    pwrstrk's Avatar
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    Re: Do I need to shock or not?

    I would SLAM it.


    Jeff
    24'x54" AG Morada RTR (by wilbar) 13'500 gal. Hayward Powerflo Matrix 1hp 2 speed. Hayward Perflex EC65 DE filter.

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    Butterfly's Avatar
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    Re: Do I need to shock or not?

    Yep, do the Slam process. Maybe the process will be short, if you caught things quickly.

    Even tho CC is is .5 and the water is clear, it sounds like you are on the verge of trouble.

    You can slam tonight and do the OCLT to confirm.

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    Richard320's Avatar
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    Re: Do I need to shock or not?

    [center:2u7ynabs][youtube:2u7ynabs]uijLXS-IJZM[/youtube:2u7ynabs][/center:2u7ynabs]
    16K freeform gunite with spa; Pentair 4000 DE filter; Century Whisperflow 1 HP; Pentair Minimax heater.
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    bobodaclown's Avatar
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    Re: Do I need to shock or not?

    When in doubt SHOCK it out!


    updated: SLAM it and move on ---http://www.troublefreepool.com/pool-school/shocking_your_pool

    Thanks for the update.
    17K Kidney Shaped Pool Concrete (Diamond Bright) Pool, 3/4 hp 2 speed 115V Sta-rite Duraglas PEA5D-180L/P2R5D-181L (Impeller C105-92PS Diffuser C1-216P), 1.5 piping, Pentair CC100 Filter , Heat Siphon 100K BTU Heat Pump Pool Heater, Flow meter Blue White Flowmeter Model No. F-30150P, Hayward Astrolight SP0581N, SWCG CalimarTitanium Edition TE45 , Dolphin Nautilus Plus with CleverClean, Lakeland Florida

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    Richard320's Avatar
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    Re: Do I need to shock or not?

    Quote Originally Posted by bobodaclown
    When in doubt SHOCK it out!
    The proper term is SLAM.
    16K freeform gunite with spa; Pentair 4000 DE filter; Century Whisperflow 1 HP; Pentair Minimax heater.
    Troublefree does not mean Maintenancefree. It's like brushing your teeth: You can spend a couple minutes a day and pennies a week or go to the dentist once a year and spend several thousand dollars.
    A pool is like a pet - you have to feed it every day, even the days you don't want to play with it!

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    Re: Do I need to shock or not?

    Thanks guys.

    another question -
    this site suggests no shocking and keeping chlorine level slightly elevated. can algae get used to higher level of chlorine?
    23k in-ground plaster. Cartridge filter Hayward 450 or 550. Hayward 2ph pump.
    liquid chlorine, tablets occasionally when out of liquid and cya allows it. ph down.
    stabilizer (Had no cya last two openings, but never before that)
    no other chemicals used in years
    TF100.

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    Mod Squad jblizzle's Avatar
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    Re: Do I need to shock or not?

    We do not recommend "elevated" chlorine levels. We recommend the APPROPRIATE chlorine levels based on the CYA level in your pool. Seems that 99+% of people (including people in the pool industry) do not grasp the relationship between the CYA and the FC.

    No, the algae will not mutate and become immune to the chlorine.

    EDIT: Welcome to TFP, btw!!!
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    Re: Do I need to shock or not?

    Right. Labeling on pool chlorine usually suggests keeping CH level 1-3, some up to 5, but never above. And I guess that assumes shocking weekly or as needed, while TFP suggests keeping chlorine level within your specific range all the time.

    Another question - if you are at the minimum according to CH\CYA and it starts raining or or just about to... do you suggest adding chlorine anyway... or wait until the rain is over and check level and add chlorine or SLAM if needed? (and once again, add or SLAM if below minimum, but above 0 and no visible algae?)
    23k in-ground plaster. Cartridge filter Hayward 450 or 550. Hayward 2ph pump.
    liquid chlorine, tablets occasionally when out of liquid and cya allows it. ph down.
    stabilizer (Had no cya last two openings, but never before that)
    no other chemicals used in years
    TF100.

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    Re: Do I need to shock or not?

    wait until the rain is over and check level and add chlorine or SLAM if needed ?
    A common "urban legend" that rainfall makes huge differences in your pool water. Unless the runoff runs into your IG pool, it doesn't.

    Read this thread and then make adjustments, if any, after it rains.

    getting-massive-rainfall-as-i-type-t66271.html
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

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    Re: Do I need to shock or not?

    We had rain most of the day yesterday. Pool was clear before the rain and looked good after with may be a couple very light shades of green or brown which looked more like dust. Right after rain I had FC 2, PH 7.8-7.9. I lowered PH to about 7.5 and then a couple hours later brought up FC to about 5-6 and had pump running for about 2-3 hours

    Tonight, about 30 hours later I have about a dozen light green spots which brush off easily. FC is 2.5, CYA is 40
    Pump was running for 8 hours (I run it during the day,9-5)

    Can FC being below minimum at some point causing this?
    Or my CYA testing is not accurate because my agent is a year last year? (leslie's CYA testing is about the same - tested twice, between 30-40.)

    I purchased taylor chlorine at leslie's this year and my reading is almost as accurate as last year's 0870 (+- .5 at most)

    Thanks.

    P.S I use liquid chlorine only
    23k in-ground plaster. Cartridge filter Hayward 450 or 550. Hayward 2ph pump.
    liquid chlorine, tablets occasionally when out of liquid and cya allows it. ph down.
    stabilizer (Had no cya last two openings, but never before that)
    no other chemicals used in years
    TF100.

  12. Back To Top    #12
    pwrstrk's Avatar
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    Re: Do I need to shock or not?

    You can't let FC fall out of range. 30 hrs is too long without adding chlorine. Your asking for trouble. You can do a OCLT test pool-school/overnight_fc_test to confirm if something is consuming your chlorine. If you fail it SLAM it.

    How does your water look.


    Jeff
    24'x54" AG Morada RTR (by wilbar) 13'500 gal. Hayward Powerflo Matrix 1hp 2 speed. Hayward Perflex EC65 DE filter.

  13. Back To Top    #13

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    Re: Do I need to shock or not?

    Quote Originally Posted by pwrstrk
    You can't let FC fall out of range. 30 hrs is too long without adding chlorine. .
    I'm sure I had about 5ppm this morning and 2.5 by 7ppm, which means most of the day it was over the minimum.

    Water looks great by the way. I just brushed the walls and poured my last two bottles, which should bring CH to about 14. I can smell chlorine though, very little, most ppl probably wouldn't smell it.. but I thought you can smell it only when it fights algae (or may be also when you can smell things most ppl can't? )
    23k in-ground plaster. Cartridge filter Hayward 450 or 550. Hayward 2ph pump.
    liquid chlorine, tablets occasionally when out of liquid and cya allows it. ph down.
    stabilizer (Had no cya last two openings, but never before that)
    no other chemicals used in years
    TF100.

  14. Back To Top    #14
    pwrstrk's Avatar
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    Re: Do I need to shock or not?

    Yea but you had some green spots. Algae.


    Jeff
    24'x54" AG Morada RTR (by wilbar) 13'500 gal. Hayward Powerflo Matrix 1hp 2 speed. Hayward Perflex EC65 DE filter.

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