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Thread: Can it be my sand?

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    Can it be my sand?

    35000 gal. pool
    liner
    sand filter
    1.5 HP pump
    pH - 7.4
    TA - 40 ppm
    CH - 90 ppm TDS - 700

    Opened 6 days ago... water very clear, bottom of pool very green (algae). Shocked with 4 gallons 4 days running. Vac. pool, brushed pool sides daily, my dolphin has been running each day... and pool floor is clear of debris (... essentially, nothing really to be worried about)... water is still very cloudy though.... teal, but cloudy... keep shocking the $%^&* out of it till it clears up. I was thinking maybe sand filter isn't filtering all particles out.... but the pressure on the filter is holding at about 12-15 psi... and i backwash when she approaches 20 psi, clears out all the %^&*( # and the pressure returns to the normal.... for the past couple of years from opening to clear water ready for swimming was about a week... so i'm frustrated....

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    Mod Squad JohnT's Avatar
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    Re: Can it be my sand?

    Welcome to TFP!

    The key pieces of information are your chlorine level and your CYA level. Being teal colored indicates your algae is dead or nearly so. Much of the US has experienced a very warm spring which makes algae grow much earlier. If your filter pressure is rising, it sounds like the filter is fine.
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    JasonLion's Avatar
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    Re: Can it be my sand?

    Try adding a little DE to the sand filter. There are instructions in Pool School.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
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    Re: Can it be my sand?

    ok this morning:
    FC - 0
    CYA - 40
    TA - 80
    pH - 7.4

    I shocked last night before bed... i've still got algae correct... shocked again this am.... just want verification that i'm following right sequence of steps... i'm new to this...

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    Mod Squad JohnT's Avatar
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    Re: Can it be my sand?

    Quote Originally Posted by eckert_m
    ok this morning:
    FC - 0
    CYA - 40
    TA - 80
    pH - 7.4

    I shocked last night before bed... i've still got algae correct... shocked again this am.... just want verification that i'm following right sequence of steps... i'm new to this...
    If you are using chlorine that fast, you surely have algae.

    The key idea you are missing is that you don't want your chlorine to get to 0ppm ever, especially when you are fighting algae. It just lets the algae get started again. If you look at the Chlorine CYA Chart, you'll see that with 40ppm CYA, you need to shock with your chlorine at 16ppm. You need to get to 16ppm, then keep it there. That's probably going to require testing and adding more chlorine every few hours at most, at least for the first day or two. These articles will guide you through the process

    Defeating Algae

    Turning Your Green Swamp Back into a Sparkling Oasis

    Shocking Your Pool
    TFP Moderator
    20K Gallon 20X36 Vinyl Inground
    Hayward S244T Sand Filter with 1HP Whisperflo Pump. Liquidator C-201 and Solar Heat

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    Re: Can it be my sand?

    alright...
    this morning
    FC - 8
    TA - 80
    CYA - 40
    pH - 7.2

    still cloudy... i would guess there is no more algae in pool due to chlorine holding over night... but why the cloudiness still... pressure on filter is still at reg. psi....

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    Re: Can it be my sand?

    How are you shocking? Are you following the process in Pool School, or just adding bags of shock?
    pool-school/shocking_your_pool
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  8. Back To Top    #8

    Re: Can it be my sand?

    when i got home from work my cya was 40 and FC was 1 so chart said i need to get FC up to 16 to shock... got it to that last night (7 jugs of liquid shock 10%)

  9. Back To Top    #9

    Re: Can it be my sand?

    I'm clear!!!!!!!!!! water FC is holding... TA, CA, and CYA are all within range.... great Memorial Day!!! thanks for the reinforcement forum folks... look forward to a great swimming season... am actually leaning toward going to salt next year... but that is a topic for another day...

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