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Thread: Need to refill pool

  1. Back To Top    #1

    Join Date
    May 2007
    Location
    Round Rock, TX
    Posts
    529

    Need to refill pool

    I had some repair work done on my pool that required it to be emptied, ARGS!

    I'll tell you it is amazing how deep the pool looks when it is empty, and those steps are tall!

    So I'm going to be filling the thing on Saturday when the tile is finished and was wondering about the best way to do it?

    My fill water has a CH of 200, TA of 200 so I already get to deal with the TA!

    Here are the numbers I'm shooting for:

    FC 4
    TA 100
    PH 7.8
    Borates 50
    CYA 70


    So I need:

    912 oz of Borax or 12 76oz boxes
    1 gallon of 6% bleach
    865 oz of MA (6.75 gallons) - added in doses with aeration in between.
    144 oz of CYA (9 lbs)

    That sound right?

    Should I fill it, then add stuff or add as it is filling? I can't imagine how long it is going to take to fill, but I'll probably use two hose bibs to fill it. Hopefully not much more than a day.

    Suggestions?
    15,500 gal, inground gunite pool with 7 ft spa, 2 speed pump 2hp/.33hp, 3/4 hp booster pump, Intermatic P1353 timer, AutoPilot SC-48, Sand filter with ZeoBest, Heater, that I never use . . .

  2. Back To Top    #2

    Join Date
    Mar 2007
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    Coastalish 'down easter'
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    Re: Need to refill pool

    Why deal with lowering the TA and trying to keep the pH so high 200 CH and 200 TA isn't a bad place to be (Langlier saturation index - wise) with a lower pH and temperate water - Richard, Evan, Jason, etc can tell you better about the other indecies but I feel less chem addition is better.

    I hope to hear more on this 8)
    Luv& Luk
    -Ted

    Having done construction and service for 4 pool companies in 4 states starting in 1988, what I know about pools could fill a couple of books - what I don't know could fill a couple of libraries :-D

    POOL SCHOOL, TF Testkits, Jason's Pool Calculator, CYA vs. cl chart, (Just a few DARNED handy links!)

  3. Back To Top    #3

    Join Date
    May 2007
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    Round Rock, TX
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    Re: Need to refill pool

    The issue I had before the exchange was a rapidly increasing PH if my TA was over 100. So I've kept it around 80-90.

    The one silver lining is that my CH was 775 before the refill . . .
    15,500 gal, inground gunite pool with 7 ft spa, 2 speed pump 2hp/.33hp, 3/4 hp booster pump, Intermatic P1353 timer, AutoPilot SC-48, Sand filter with ZeoBest, Heater, that I never use . . .

  4. Back To Top    #4

    Join Date
    Mar 2007
    Location
    Coastalish 'down easter'
    Posts
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    Re: Need to refill pool

    OH

    No need to be reasonable 8)

    I've said hundreds of times that 'a pool owner who knows their pool can care for it better than I can' - the trouble is that I usually only get sent out to the pools that the owner doen't care for nor know I'll trust you on this one
    Luv& Luk
    -Ted

    Having done construction and service for 4 pool companies in 4 states starting in 1988, what I know about pools could fill a couple of books - what I don't know could fill a couple of libraries :-D

    POOL SCHOOL, TF Testkits, Jason's Pool Calculator, CYA vs. cl chart, (Just a few DARNED handy links!)

  5. Back To Top    #5
    JasonLion's Avatar
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    May 2007
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    Silver Spring, MD
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    37,879

    Re: Need to refill pool

    I would wait to add chemicals until you have the pump running. That way you will have good circulation when adjusting levels. Particularly with bleach and muriatic acid, you don't want the chemicals sitting against the liner for even the short time it takes for them to mix in when the pump isn't running.

    I expect that between lowering the TA and adding borates you will need more acid than that. Lowering TA will take a while, so plenty of opportunities to go out and buy more
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  6. Back To Top    #6

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    Mar 2007
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    San Rafael, CA USA
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    Re: Need to refill pool

    You're going to need 437 ounces of Muriatic Acid just to compensate for the pH from the Borax, but the addition of the CYA (which is acidic) reduces that need to 349 ounces of Muriatic Acid. So I'd figure something in this ballpark, but you should test the pH and adjust accordingly, but don't raise the pH unless it's below 7.0 (or the next to lowest reading on your pH test) since you want to lower the TA next.

    Then, as far as lowering the TA is concerned, you'll add more acid to get to the low pH. As for how much acid it will taketo get from a TA of 200 to 100 (actually, a carbonate alkalinity from 200 to 72.5), that's around 505 ounces of Muriatic Acid total (not added all at once, of course, but over time to keep the pH low and while aerating).

    So all told, I get around 854 ounces of Muriatic Acid (349 + 505) that will be needed -- about what you estimated.

    As far as what to add while filling, I think only chlorine and some CYA is needed initially since your water already has plenty of CH and TA to protect plaster (though over a very short time that's not a problem anyway). I'm not sure how best to get the CYA into the water initially unless you start your filling after the sun is mostly off the pool (i.e. there is nothing to dissolve the CYA into initially and you can't use your skimmer or pump/filter for that). After you've filled up the pool, then you can add the Borax and acid and get the pH into the low range and then start your aeration plus additional acid addition to lower the TA.

    Richard
    16,000 gallon outdoor in-ground 16'x32' plaster pool; Pentair Intelliflo VF pump; Pentair IntelliTouch i9+3s control system; Jandy CL-340 square foot cartridge filter
    12 Fafco solar panels; Purex Triton PowerMax 250 natural gas heater (200,000 BTU/hr output); automatic electric pool safety cover; 4-wheel pressure-side "The Pool Cleaner"

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