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Thread: High CYA

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    Join Date
    Jan 2016
    Location
    los angeles,ca
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    13

    High CYA

    Hi,

    Last week when I tested the water it showed higher PH and so I added Muriatic acid. Added about half a gallon. It is a 20,000 gallon pool.

    This week when I tested the water at local store they said I have high CYA. It is at 150 ppm. Is it real high? Watched some youtube videos and they say it should be around 30 and they recommend adding Bio Active.

    Should I add Bio Active? Is it a problem having CYA that high?

    Thanks a lot.

  2. Back To Top    #2

    Re: High CYA

    Bio active is not a recommended product. I would not use it.

    150 is too high. Best is to get your own test kit and test yourself and then do a partial drain and refill as needed to lower CYA.

    How did you pH get high while the CYA also got high?

    What are all of your other readings?

  3. Back To Top    #3

    Join Date
    Jan 2016
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    los angeles,ca
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    Re: High CYA

    My test kit was always showing high PH and I did not test for CYA back then. I should have tested for CYA before adding acid.

    My numbers are below.

    Free chlorine 8
    Total Chlorine 8
    Calcium 800
    CYA 150
    Total Alkalinity 100
    PH 7.7
    Phosphates 1500

    At this 150 level will it affect the pool equipment or it will be bad for the skin if we swim in it?
    I am hopping it will come down by itself after some time.

    If I have to drain, how much water I have to drain?

    Thanks

  4. Back To Top    #4
    Mod Squad pooldv's Avatar
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    Aug 2012
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    Re: High CYA

    PH and CYA do NOT effect each other. You probably want to have your CYA at 50 or 60 at the most. So, about 2/3 drain and refill. If your pool is vinyl liner be sure to leave a foot of water in the shallow end when draining. If it is gunite check to be sure you aren't in a high water table area that could float your pool shell if your drain too much.

    The problem is that the chlorine level is set based on the CYA level and the Chlorine CYA Chart. Above 100 just requires too much chlorine to manage and the PH test does not work when FC is above 10.

    Read here for a better understanding of water chemistry, Pool School - ABCs of Pool Water Chemistry

    Also add your pool info to your signature so that we can better help you. More here, Pool School - Read This Before You Post

    EDIT: PH and CYA do NOT effect each other, left out the most important word!
    TFP Moderator
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    2012 build and pics, 20k gal gunite, black onyx pebblesheen, OK flagstone, IntellifoVS, cart filter w/Pleatco, IC40 SWG, Solartouch, 5 12'x4' solar panels, HP50HA heat pump, 8mil solar cover, borates, TF-100 test kit, SONOS, Doheny's Discovery Robot, hot tub on bleach

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    Mod Squad tim5055's Avatar
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    May 2014
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    Columbia, SC
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    Re: High CYA

    I really think you need to do a little reading to better understand how all of these things work. Start with ABCs of Pool Water Chemistry
    TFP Moderator 39 X 18 23,000(ish) freeform gunite; built 2007ish; Pentair Triton II TR100 600lb Sand filter; 2 HP Pentair pump with 2.2 HP AO Smith single speed motor; 2 skimmers, 1 main drain, 4 returns w/waterfall, Stenner 45MHP2 3GPD running@ 60% - 15 gal Tank; heated by the sun CYA 200+ when I started - 50 now. Dolphin Supreme M5 Pool Cleaner. Hot Springs SX Spa, 285 gallon

  7. Back To Top    #7

    Join Date
    Jan 2016
    Location
    los angeles,ca
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    Re: High CYA

    Using tablet in the floater.
    30 year old pool, 14x30 plaster (15k gal). DE filter. Hayward heater. HDX pool spa basic test kit.

  8. Back To Top    #8
    Mod Squad tim5055's Avatar
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    Re: High CYA

    Quote Originally Posted by lalapool View Post
    Using tablet in the floater.
    This is why you have high CYA. Tablets are almost half CYA.
    TFP Moderator 39 X 18 23,000(ish) freeform gunite; built 2007ish; Pentair Triton II TR100 600lb Sand filter; 2 HP Pentair pump with 2.2 HP AO Smith single speed motor; 2 skimmers, 1 main drain, 4 returns w/waterfall, Stenner 45MHP2 3GPD running@ 60% - 15 gal Tank; heated by the sun CYA 200+ when I started - 50 now. Dolphin Supreme M5 Pool Cleaner. Hot Springs SX Spa, 285 gallon

  9. Back To Top    #9

    Re: High CYA

    Tabs are acidic so it doesn't make sense that your pH has been rising.

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