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Thread: Pool CYA/SLAMing order of adjustment

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    Pool CYA/SLAMing order of adjustment

    Hello pool-goers,

    I am doing my 1st opening and think I have a situation I've read about on the boards. When I closed the pool last fall, I had a CYA of 60. I started the opening process about 3 days ago (of mostly cleaning and filtering only) and today I read my CYA at 0 (or at least less than 20 which is the maximum of the test kit sight glass). Also, my pH is high, above 8.0. I'm guessing that the algae over the winter consumed my CYA and converted it into ammonia, which would explain the low CYA and high pH readings.

    I have added 2 10ppm additions of 12.5% bleach to my pool over the past hour. I didn't bother doing a FC test yet, because I can't even see the bottom of my pool so I'm assuming the ammonia and/or algae are consuming all of it at these early shocks.

    Should I be trying to lower the pH right now? Should I also be adding CYA right now? I don't know if that would be worth the effort until I break down the ammonia (I don't have an ammonia test strip, so I'm just assuming it's there). Or should I just continue to shock with chlorine every 30 min-1hr?

    p.s. - did not adjust chemistry over winter, and did not cover the pool (this pain of cleaning has convinced me of the need to upgrade that before next season).

    Thanks,
    ~20k gal inground vinyl lined pool
    Hayward Perflex DE filter
    Aqua bot cleaner

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    Smykowski's Avatar
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    Re: Pool CYA/SLAMing order of adjustment

    Yes, the correct order for SLAMing is to adjust pH first, then SLAM. In your case, you need to know what's happening to the FC before you move to a next step. If the FC is below 10, you can adjust your pH, but let us see the latest test results before you go much further than that.
    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
    The most important article on this site - The ABCs of Pool Water Chemistry

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    Re: Pool CYA/SLAMing order of adjustment

    Did my FAS DPD test:

    2ppm FC, 10.5ppm CC

    This is ~1 hr since my 2nd addition of ~10ppm chlorine (and 1.5 hrs since the first addition of 10ppm chlorine)

    So I should do some pH lowering?
    ~20k gal inground vinyl lined pool
    Hayward Perflex DE filter
    Aqua bot cleaner

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    pwrstrk's Avatar
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    Pool CYA/SLAMing order of adjustment

    You can lower PH now if FC is 2. That is a very high CC. The FC and CC are correct right ? Not the other way around CC 2 FC 10.5.
    If they are correct you most certainly have ammonia. You'll go thru a lot of bleach to get rid of 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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    Re: Pool CYA/SLAMing order of adjustment

    Yes it's correct. When I did CC, it was only faintly pink. When I went on to add the CC reagent, it was SUPER pink.

    Should I also be adding CYA now? Will that interfere with this ammonia problem?
    ~20k gal inground vinyl lined pool
    Hayward Perflex DE filter
    Aqua bot cleaner

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    pwrstrk's Avatar
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    Pool CYA/SLAMing order of adjustment

    When you did your FC test you added drops till it went completely clear. You then should have went right to the CC test then. If you let the sample set a bit it will go back to a slight pink.
    I'm not sure about the ammonia effecting the CYA.
    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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    frustratedpoolmom's Avatar
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    Re: Pool CYA/SLAMing order of adjustment

    You need a little CYA to protect the FC from sunlight. Add enough to reach 20 ppm. Add chlorine up to 10ppm of 12.5 every 20 to 30 minutes and test your FC, if you don't hit 10, recalculate and keep adding it every 20-30 minutes. Test the FC. Early on the ammonia consumes it instantly, which is why hitting it hard up front is key, you'll actually use less chlorine in the long run. Put the CYA in a sock or a nylon and it can dissolve while your hitting the ammonia. Don't bother testing the CC (save your reagent) until you can actually hold a FC of 10 for more than an hour. Once you test the CC at that point you'll find it's down to the 1-2 range which indicates the ammonia is being eradicated. I've cleared probably 15-20 ammonia pools - hitting it hard for the first 4 hours does work. Expect to use 3-5 cases.

    - - - Updated - - -

    Don't wait an hour. 30 min at most. The addition of CYA won't create more ammonia as long as you are constantly attacking with chlorine.
    Helpful links: Pool School; CYA/Chlorine Chart
    24' round AG pool, 52" high, Raypak heater; Waterway 2 spd Pump;
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    Re: Pool CYA/SLAMing order of adjustment

    Alright, trying to follow those instructions, although if it goes too late, I'm going to bed...hope I don't have to start over

    I didn't have a sock handy so I just broadcast the 20ppm of CYA, hope that doesn't matter.

    I've added 5 gal of 12.5 chlorine so far, last FC measurement was only 1ppm
    ~20k gal inground vinyl lined pool
    Hayward Perflex DE filter
    Aqua bot cleaner

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    pwrstrk's Avatar
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    Pool CYA/SLAMing order of adjustment

    Should have put the CYA in a sock and hung it in front of a return. Don't broadcast it anymore. Not a good practice ! It could fade your liner with it just laying there. 😳
    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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    Re: Pool CYA/SLAMing order of adjustment

    Ah. good to know for the future. Fading is okay...my liner is already 30 years old and extremely faded, planning to do a pool renovation either this fall or next spring.
    ~20k gal inground vinyl lined pool
    Hayward Perflex DE filter
    Aqua bot cleaner

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    frustratedpoolmom's Avatar
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    Re: Pool CYA/SLAMing order of adjustment

    Keep at it!

    They don't wear socks where you live?
    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: Pool CYA/SLAMing order of adjustment

    the trick is to find a sock I don't like
    ~20k gal inground vinyl lined pool
    Hayward Perflex DE filter
    Aqua bot cleaner

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    Re: Pool CYA/SLAMing order of adjustment

    8 gal of 12.5% chlorine so far...last FC reading was 0.5ppm (before that it was 1ppm).

    Going to have to buy a few more 5 gal jugs tomorrow.
    ~20k gal inground vinyl lined pool
    Hayward Perflex DE filter
    Aqua bot cleaner

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    Re: Pool CYA/SLAMing order of adjustment

    By the way, how often should I be "backwashing" (draining) my DE filter? I've mostly been bumping it during this process. And of those times I backwash, how often should I be adding DE?
    ~20k gal inground vinyl lined pool
    Hayward Perflex DE filter
    Aqua bot cleaner

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    pwrstrk's Avatar
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    Pool CYA/SLAMing order of adjustment

    In your case with the bump type, bump it when the pressure rises 25% over clean pressure. If it rises back up 25% over clean pressure pretty quickly then I would backwash. If you have any algae I wouldn't bother bumping it when the pressure rose 25%, I would just backwash and recoat at that point.
    You add DE every time you backwash. It's not good to use filter with no DE on the flex tubes. Only add 80% of a full charge to it after a backwash. If you so a complete tear down and clean then add full amount of DE.
    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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    Re: Pool CYA/SLAMing order of adjustment

    Quick question I'm dealing with asme issue on day 3 now. Should I clean the de filter fingers in muriatic acid after I get it cleaned out ? I have already hosed out the filter 3 times. Might have to do it again soon. Also how do most of you guys catch the de ? I've been trying to use a bucket... But wondering what to do with my growing collection of de.


    31000 gallon in ground vinyl
    1 HP Hayward SuperPump
    65 sq DE filter

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    Re: Pool CYA/SLAMing order of adjustment

    okay, FC is starting to rise. I was worried I'd have to start over this evening after 18 hrs of no shocking, but I guess that wasn't the case.

    pH is now 7.2
    TA is ~130-170
    started shocking and assuming FC=0 start this afternoon, after 1st shock FC +30min was 4.5ppm, +30min from 2nd shock was 6.5ppm
    +
    Water is still very murky but less green (more teal). Cannot see bottom of deep end yet.
    ~20k gal inground vinyl lined pool
    Hayward Perflex DE filter
    Aqua bot cleaner

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    Re: Pool CYA/SLAMing order of adjustment

    Nice glad to hear it's cleaning up for you. I gotta go get water and test mine now.


    31000 gallon in ground vinyl
    1 HP Hayward SuperPump
    65 sq DE filter

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    Re: Pool CYA/SLAMing order of adjustment

    Still a ways to go but as of tonight about 5ppm consistent FC loss for 2 hourly shocks.

    When does algicide addition come into play? Should I add some now or not until the pool is clear?
    ~20k gal inground vinyl lined pool
    Hayward Perflex DE filter
    Aqua bot cleaner

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    pwrstrk's Avatar
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    Pool CYA/SLAMing order of adjustment

    No algicide's are needed. Get done with the SLAM process and maintain your FC in range for your CYA level and you won't have algae !
    Keep maintaining SLAM level as best you can. 😎
    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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