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Thread: Chemistry After Water Replacement

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    Join Date
    Jun 2008
    Location
    Thornton, PA
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    76

    Chemistry After Water Replacement

    Folks-

    I replaced ~ 14K gallons of my water below is my old, (prior to refill) new, and fill water chemistry.

    Old Water (before the replace)

    Date: 8/14
    Temp: 85F
    FC: 1
    CC: .5
    TC: 1.5
    T/A: 45
    C/H: 650
    CYA: 50
    Salt: 3,200ppm
    pH: 8.0
    Filter pressure: 22 PSI
    SWG Setting: 20%
    Pump Run Time: 8 Hrs./ day
    Heat Pump: Standby

    Action taken after readings gathered:

    Replaced 50% of the water.

    ##########################
    Fill Water: (two hoses)
    Date: 8/15
    Temp: ~60F
    FC: .5
    CC: .25
    TC: .75
    T/A: 65
    C/H: 100
    CYA: 0
    Salt: N/A
    pH: 8.0

    Action take:
    Added 2 gallons of MA
    Added 160 lbs salt (still need to add more)
    Added 3 gallons bleach.
    ##########################

    New water:

    Date: 8/17
    Temp: 72F
    FC: 1.5
    CC: .5
    TC: 2
    T/A: 20
    C/H: 410
    CYA: 25
    Salt: 2,400ppm
    pH: 7.0
    Filter pressure: 22 PSI
    SWG Setting: 0%
    Pump Run Time:24/7
    Heat Pump: Standby
    Additional information: it rained ~3" last night, had to drain some water this am before testing!!

    So, I see that my salt, CYA, TA and pH are too low.

    My action plan is as follows:

    Add another 140 lbs salt -then,turn on SWG to 50% (FC Target: 3.0)
    Add 13 lbs of CYA to get CYA Levels to 80
    Add 21 lbs of baking soda to bring TA up to 70

    I figure that the baking soda, and SWG will bring the pH up so I'll wait to see if adding that is enough before correcting that.

    Would you folks do any else/ differently?

    Thanks!

    Dan
    28K Gal. 802 Sq Ft., Free Form, IG, Gunnite with Midnight Maui Hydrazzo Carlton Pool. Exposed Aggregate Decking. Jandy DE Filter, 1.5 HP Jandy Pump, SWCG. Zodiac 380 pressure-side cleaner. Completed Construction: May 2008.

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    Richard320's Avatar
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    San Dimas, CA (LA County)
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    Re: Chemistry After Water Replacement

    I'd get some more bleach in there ASAP, so there's something keeping things clean until the SWG can catch up. And I would aim low on the CYA. It's easier to add more later than it is to remove excess.
    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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    duraleigh's Avatar
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    Apr 2007
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    Sebring, Florida
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    Re: Chemistry After Water Replacement

    I would probably target a CYA of around 60 at first and let things settle in. Then, I would retest and adjust if necessary or perhaps just leave it alone if your season is closing down.

    You're smart to leave pH alone. It'll come up

    Ditto what Richard says about the chlorine.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

  4. Back To Top    #4

    Join Date
    Jun 2008
    Location
    Thornton, PA
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    Re: Chemistry After Water Replacement

    So, in my haste I bought "Washing Soda" 4/ 5lb boxes. I added one, 5lb box and things clouded up really badly. Oops.

    Edit: it actually A&H "Super Washing Soda"

    So I stopped, and did not add the other 3.

    How badly did I mess this up?

    Will/ should the filter clean this up?

    Feeling a bit stupid...
    28K Gal. 802 Sq Ft., Free Form, IG, Gunnite with Midnight Maui Hydrazzo Carlton Pool. Exposed Aggregate Decking. Jandy DE Filter, 1.5 HP Jandy Pump, SWCG. Zodiac 380 pressure-side cleaner. Completed Construction: May 2008.

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    Thornton, PA
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    Re: Chemistry After Water Replacement

    According to the MSDS, A&H Super Washing Soda is made up of 85% Sodium carbonate, 15% water. I also read where it reacts with acid to produce CO2 gas, could it be reacting with my low pH, or the CYA I added?

    Just guessing.

    Dan
    28K Gal. 802 Sq Ft., Free Form, IG, Gunnite with Midnight Maui Hydrazzo Carlton Pool. Exposed Aggregate Decking. Jandy DE Filter, 1.5 HP Jandy Pump, SWCG. Zodiac 380 pressure-side cleaner. Completed Construction: May 2008.

  6. Back To Top    #6

    Join Date
    Jun 2008
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    Re: Chemistry After Water Replacement

    OK, so the pool is clearing up now. Feeling relieved. So from what I can gather, I managed to take steps that are aimed at increasing pH, not so much TA. -Although, I get that they're related.

    I'm thinking I'm going to keep my remaining Washing Soda, not use it just now, it makes the water scary-cloudy, and go out and buy 15 lbs of Baking Soda. Should I expect the Baking Soda to cloud up the water as much?

    Thanks,

    Dan
    28K Gal. 802 Sq Ft., Free Form, IG, Gunnite with Midnight Maui Hydrazzo Carlton Pool. Exposed Aggregate Decking. Jandy DE Filter, 1.5 HP Jandy Pump, SWCG. Zodiac 380 pressure-side cleaner. Completed Construction: May 2008.

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