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Thread: Water replacement

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    Water replacement

    We are having to replace a lot of water (water fell just about almost at the bottom of the skimmer).

    When is the best time to test after replacing water is complete, in which I will get the most accurate reading of all categories (biggest concerns are CYA and chlorine, I would think)? An hour, two hours, three hours, etc?
    7+ years, inground, 25,000 gallon, vinyl, sand filter.

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    Mod Squad Bama Rambler's Avatar
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    Re: Water replacement

    If the pump is running an hour is more than enough time.
    Dave J. TFP Moderator
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    Re: Water replacement

    Ok, thanks!

    Are chlorine and CYA really the only that are most affected when it comes to water replacement? Or can pH and TA be significantly affected as well? Not sure what I'm in for
    7+ years, inground, 25,000 gallon, vinyl, sand filter.

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    msgtdan's Avatar
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    Re: Water replacement

    It depends on your fill water. You can test it and get a general idea. I have high TA & CH fill water so I know those will be affected when I add water, which I did last night.
    Dan D
    Used 2003 Aqua Leader 27'x52", 17,800 w/10" hopper, SwimPro SW256T 250# sand filter, Hayward PowerFlo LX pump 1hp impellor, Emerson 1 1/2 hp motor, setup Aug 2012 Summer 2011 used Summer Escapes Ring pool 14' x 42", Intex 1600gph sand filter, HTH 6 way test kitTF-100 w/stirrer, Well water @ FC=0, PH=7.2, TA=290, CH=320

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    Re: Water replacement

    I actually tested earlier and everything looked okay but the pH, which went from 7.5 to 7.2. Earlier today (Eastern Time) around 1:00, I added 15 oz of soda ash to bring the pH up gradually to 7.3 (last time I added too much so I am being conservative) but my pH hasn't budged. It looks like it may have went down, maybe from all the new water filtering through the past few hours.

    Anyway, should I add more soda ash at this point? How long does it take for soda ash to kick in and raise the pH once added? Thinking whatever I added was surely not enough, but afraid to add more in case it needs more time to adjust.
    7+ years, inground, 25,000 gallon, vinyl, sand filter.

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    Re: Water replacement

    PH & TA interact with each other, it really depends on where your at, what your fill water is like. I've never added anything to raise PH because with my high TA, PH is going to come up and I'll have to bring it back down. If you have low TA & PH for fill water then you may have to adjust. If you'd post some numbers maybe we could tell you what to expect.
    Dan D
    Used 2003 Aqua Leader 27'x52", 17,800 w/10" hopper, SwimPro SW256T 250# sand filter, Hayward PowerFlo LX pump 1hp impellor, Emerson 1 1/2 hp motor, setup Aug 2012 Summer 2011 used Summer Escapes Ring pool 14' x 42", Intex 1600gph sand filter, HTH 6 way test kitTF-100 w/stirrer, Well water @ FC=0, PH=7.2, TA=290, CH=320

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    Re: Water replacement

    FC = 2 (getting that adjusted now)
    TA = 90/100
    pH = 7.2 (7.1 or so)
    CYA = 40

    My pH has a tendency to drop rather than increase.
    7+ years, inground, 25,000 gallon, vinyl, sand filter.

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    Re: Water replacement

    Do you use trichlor pucks to chlorinate with? I know those will drive PH down other than that we'd have to get others more expert than I in here. If you are using Trichlor or Dichlor both add CYA which you don't want to raise much more.
    Dan D
    Used 2003 Aqua Leader 27'x52", 17,800 w/10" hopper, SwimPro SW256T 250# sand filter, Hayward PowerFlo LX pump 1hp impellor, Emerson 1 1/2 hp motor, setup Aug 2012 Summer 2011 used Summer Escapes Ring pool 14' x 42", Intex 1600gph sand filter, HTH 6 way test kitTF-100 w/stirrer, Well water @ FC=0, PH=7.2, TA=290, CH=320

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    Re: Water replacement

    Quote Originally Posted by msgtdan
    Do you use trichlor pucks to chlorinate with? I know those will drive PH down other than that we'd have to get others more expert than I in here. If you are using Trichlor or Dichlor both add CYA which you don't want to raise much more.
    Nope...Just liquid chlorine. The pH was good until we had to add water. We're having company tomorrow so I want to be sure it stays sparkling like it is (but not counting on a ton of aerating though...small swimmers )! Worried about the pH being too low right now. I'll probably have to add a bit more soda ash as I don't want TA going up too much more either, but think we'll have to do something about the low pH so it doesn't get lower.
    7+ years, inground, 25,000 gallon, vinyl, sand filter.

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    Re: Water replacement

    I would say you need the water well blended, this partly depends on run time of the pump, but if you are not using a bottom drain and not just a skimmer it will also depend on the temperature of the fill water. For example if you have a well and 60 degree fill water, being added to 85 degree pool water, the majority of the fill water will sink to the bottom of the pool and stay there.
    Indoor 20x40 35,000 gallon vinyl pool with 1.5 HP 2 speed Jandy FloPro pump, Hayward EC75 Perflex DE filter, 11 4x12 Techno-Solis solar panels w/ Aquasolar controller, Aquabot Turbo T Robot Cleaner. Also LMI metering chlorine dispenser pump and HotSpring Jetsetter
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    Re: Water replacement

    Quote Originally Posted by Isaac-1
    I would say you need the water well blended, this partly depends on run time of the pump, but if you are not using a bottom drain and not just a skimmer it will also depend on the temperature of the fill water. For example if you have a well and 60 degree fill water, being added to 85 degree pool water, the majority of the fill water will sink to the bottom of the pool and stay there.
    How long would it take to be well blended? Does this mean my results right now may not be accurate? The filter has been running for about 4 to 5 hours since adding the water. I believe we are just using the skimmer, not the bottom drain.
    7+ years, inground, 25,000 gallon, vinyl, sand filter.

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    Re: Water replacement

    The question would then be is your fill water much warmer or colder than your pool water, if it is you may still not be well blended (cold water sinks)
    Indoor 20x40 35,000 gallon vinyl pool with 1.5 HP 2 speed Jandy FloPro pump, Hayward EC75 Perflex DE filter, 11 4x12 Techno-Solis solar panels w/ Aquasolar controller, Aquabot Turbo T Robot Cleaner. Also LMI metering chlorine dispenser pump and HotSpring Jetsetter
    I use and endorse TFtestKits TF-100 from http://tftestkits.net
    ~Remember TFP counts on your donations to keep this site ad free~

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    Re: Water replacement

    Quote Originally Posted by Isaac-1
    The question would then be is your fill water much warmer or colder than your pool water, if it is you may still not be well blended (cold water sinks)

    Thanks guys. Didn't even think about the cold water sinking and taking much longer to blend The fill water is cold.
    7+ years, inground, 25,000 gallon, vinyl, sand filter.

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    Re: Water replacement

    Point one of your returns downward to help mix.
    15'x48" 4500 gallon Intex pool, buried 1.5 ft. Pac-Fab Dynamo 3/4 hp pump. Hayward S180T sand filter, bought used. Taylor K-2006 test kit. Rocket mass heater based wood fired pool heater.

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