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Thread: Shock or adjust PH first

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    Shock or adjust PH first

    I'm uncovering my pool tomorrow but filled with about 6 inches of new water to raise water level today. Once I pull the cover tomorrow do I start the shocking process first or adjust the PH if it's a little off first.
    Southern NJ, 1 HP Haward Pump, 16x 32 dimensions, 21,000 gallon vinyl liner inground pool, TF-100 test kit.

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    Smykowski's Avatar
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    Re: Shock or adjust PH first

    Definitely. FC is more effective in the low 7s.
    33' round, 23,000 gal AG vinyl , 1HP 2spd PowerFlo Matrix downsized with 3/4HP impeller (X2), Hayward S180T 150# sand filter (X2), Hayward H250 NG heater Pool Store year 1 - $850 for 2 months; Pool Store year 2 - $440 for 2 months, TFPC year 1 - $170 for 4 months; TFPC year 2 - $95 for 4.5 months
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    Re: Shock or adjust PH first

    Quote Originally Posted by Bobswe
    I'm uncovering my pool tomorrow but filled with about 6 inches of new water to raise water level today. Once I pull the cover tomorrow do I start the shocking process first or adjust the PH if it's a little off first.
    Start with a full set of tests. If the water's clear, you may not need to do the shock process. On the other hand, if CYA is astronomical, you may want to drain and replace some water first.

    That said, Absolutely pH first. And once it's good, don't bother testing pH again until the shock process is complete and FC has dropped below 10. High chlorine reacts with the reagent and shifts the color, so it won't be accurate.
    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: Shock or adjust PH first

    Getting the pH down to low 7s is actually PART of the shock process. So it's really something that should be done as step one.

    Shocking:

    Check and adjust the PH to the low end of the normal range. Remember, the PH test isn't reliable during shocking so make sure to take care of this before you start.
    18x36 inground vinyl lined, Hayward sand filter and tablet chrolinator, approx 18k gallon

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    Re: Shock or adjust PH first

    Great advice. Thank to you all.
    Southern NJ, 1 HP Haward Pump, 16x 32 dimensions, 21,000 gallon vinyl liner inground pool, TF-100 test kit.

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    Re: Shock or adjust PH first

    Again my filter was running and water circulating but I tested the water by reaching under the cover and came up with the following readings.
    TC 0
    TA 180
    CAL 170
    PH 7.2
    CYA 0 (thought this was odd because I did have a reading of around 80 last year)
    Any suggestions?
    Southern NJ, 1 HP Haward Pump, 16x 32 dimensions, 21,000 gallon vinyl liner inground pool, TF-100 test kit.

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    frustratedpoolmom's Avatar
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    Re: Shock or adjust PH first

    Sometimes over the winter CYA can convert to ammonia, after rainwater runoff sends soil bacteria into the pool water - the bacteria can convert the CYA to ammonia. This creates a huge chlorine demand at start up.

    When you begin the shock process, if this is indeed what happened, the FC will be consumed virtually immediately and the ammonia will register as very high CCs. If you see this, I would suggest you purchase an ammonia test kit from a petshop (its a fish tank supply item) and get an idea of how high. The ratio of chlorine needed to oxidize ammonia is like 10 to 1, so it might be easier to drain some of the water to lower the level. I would confirm this before proceeding the amount of chlorine needed it could be cheaper to just replace some of the water to lower the level. You would wanna do this before adjusting CYA for obvious reasons as water replacement affects the CYA level. Then once you confirm if this is your issue you can proceed with adding a new dose of CYA.
    Helpful links: Pool School; CYA/Chlorine Chart
    24' round AG pool, 52" high, Raypak heater; Waterway 2 spd Pump;
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    Re: Shock or adjust PH first

    And the TA level?
    Southern NJ, 1 HP Haward Pump, 16x 32 dimensions, 21,000 gallon vinyl liner inground pool, TF-100 test kit.

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    Re: Shock or adjust PH first

    Quote Originally Posted by Bobswe
    And the TA level?
    It's only useful right now to calculate the acid dose.

    Once the pool is clear, balanced, and sparkly, you can play with lowering it to stave off boredom. It's not harmful by itself - you drink and bathe in the same fill water. It will come down on its own if you faithfully keep pH adjusted. It's only worrisome if you have high CH or you're going to add borates.
    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: Shock or adjust PH first

    So I shocked the pool yesterday and by today the FC reading was 0. I can see the deep end of the pool but water is tinted (I call it aqua and my kids call it mint green). I had copper and Iron tested in 2 places and both read 0 but in years past I have had a copper reading (I'm waiting on an order of Pro Teams Metal Magic which is expected to arrive sometime tomorrow) I went to the local Petsmart and got an ammonia test. The reading did show 3.0 in ammonia. I'm leary of water replacement because my liner is suspect so would prefer to kill by shocking. My CYA shows 0-10 so I bought 5 lbs of stabilizer to start. How do you recommend I proceed? Should I add the stabilizer while I shock or do it after. Will the ammonia decrease in time if I keep the water properly sanitized by adding liquid chlorine more often? I love the pool season but get discouraged with this kind of stuff. Any help would help..
    Southern NJ, 1 HP Haward Pump, 16x 32 dimensions, 21,000 gallon vinyl liner inground pool, TF-100 test kit.

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    frustratedpoolmom's Avatar
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    Re: Shock or adjust PH first

    Breaking Down Ammonia:
    http://www.troublefreepool.com/openi...nia-t6711.html

    Testing Extreme Chlorine Demand
    http://www.troublefreepool.com/post56824.html#p56824

    You should read both, and do the second - and try to get a guestimate of how much chlorine you are looking at.

    Yes you will need to get CYA in there but start adding it when you begin to attack the pool - if the FC is zero any CYA you add could potentially continue to convert to ammonia.
    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
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    Re: Shock or adjust PH first

    I can tell you shocking the pool once with ammonia present will get you no where. In ammonia situations you have to test and add HOURLY. I have eradicated it from several pools but had to have the homeowner's participation. With the weekend coming up, I would spend today and tomorrow stocking up and forming a plan of attack - the initial doses will be completely consumed within hours.
    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
    http://www.PerfectlyClearPoolService.com

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    Re: Shock or adjust PH first

    I am off so can stay at it but what FC reading so I keep pool at? And can I add the stabilizer now?
    Southern NJ, 1 HP Haward Pump, 16x 32 dimensions, 21,000 gallon vinyl liner inground pool, TF-100 test kit.

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    frustratedpoolmom's Avatar
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    Re: Shock or adjust PH first

    Start by targeting a FC shock level of 10, add the CYA today, enough to reach 30. Then tomorrow use 12 as your target, as we "assume" the CYA level is in there. The rest of the process, 12 will be your target. You can raise the CYA later after the shock process is complete (if you will be using bleach as your chlorine source.)
    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
    http://www.PerfectlyClearPoolService.com

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    Re: Shock or adjust PH first

    I started the shocking process but am having a hard time getting a FC reading at all. Using the pool calculator I e been adding 167 oz of liquid pool shock but it still doesn't move the fc reading. Am I doing something wrong?
    Southern NJ, 1 HP Haward Pump, 16x 32 dimensions, 21,000 gallon vinyl liner inground pool, TF-100 test kit.

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    Richard320's Avatar
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    Re: Shock or adjust PH first

    Quote Originally Posted by Bobswe
    I started the shocking process but am having a hard time getting a FC reading at all. Using the pool calculator I e been adding 167 oz of liquid pool shock but it still doesn't move the fc reading. Am I doing something wrong?
    You could be testing wrong, or you have Ammonia, as mentioned earlier in the thread. Did the CC reading get real big?
    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: Shock or adjust PH first

    Yes, the cc reading got high. I've decided to do a partial drain and just started. How far down on a 32 by 16 lynal pool can u safely drain. I'm thinking 2 feet? It has an 8 ft deep end and 3 foot shallow. What's ur opinion on drain depth?
    Southern NJ, 1 HP Haward Pump, 16x 32 dimensions, 21,000 gallon vinyl liner inground pool, TF-100 test kit.

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    Richard320's Avatar
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    Re: Shock or adjust PH first

    Quote Originally Posted by Bobswe
    Yes, the cc reading got high. I've decided to do a partial drain and just started. How far down on a 32 by 16 lynal pool can u safely drain. I'm thinking 2 feet? It has an 8 ft deep end and 3 foot shallow. What's ur opinion on drain depth?
    If you leave a foot in the shallow end you'll be fine.
    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: Shock or adjust PH first

    Even with stairs in the shallow end, not a ladder?
    Southern NJ, 1 HP Haward Pump, 16x 32 dimensions, 21,000 gallon vinyl liner inground pool, TF-100 test kit.

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    frustratedpoolmom's Avatar
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    Re: Shock or adjust PH first

    Yes. The ammonia consumes the chlorine immediately at first. Stay at it, test every 30 minutes for a while.
    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
    http://www.PerfectlyClearPoolService.com

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