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Thread: High CH and CYA - when to dump/refill h20?

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    High CH and CYA - when to dump/refill h20?

    We are new to the forum and new pool owners (first season) in N.Texas w/20000 gunnite pool. We have been following previous owners maintanence instructions which uses pool store/test supplies. After becoming familiar with forum (which is great) we're converting to BBB method. TF100 test kit ordered, recieved today and test indicates our CYA and CH levels are high. (These is reasonably consistent with what pool store has been telling us but it is difficult to sort thru the smoke and mirrors) Test results are:

    FC 4.5
    CC .5
    TC 5.0
    TA 190
    CH 600
    CYA125

    We've been using 3" 94% triclor pucks and pool water has been sparkling, no problems. Once the triclor pucks are gone/used up I'm thinking we'll switch to liquid chlorine. With the CH and CYA as high as it is, pool calculator says drain/fill 68% new, it seems like we're going to have to bite bullet and drain/fill.

    Questions:
    Am I on right track and drain/fill immenent? Is it best or good reason to do this right away or wait until next pool season (after winter)

    If i refill should I do this after the triclor pucks are gone or refill use the pucks to contribute to the CYA that I understand they give off.

    Anyway I'm thinking a planned drain/refill is better than waiting until its forced due to CYA levels making chlorine ineffiective and algea can't be controlled.

    Also, pool store keeps telling us due to high CH levels, we'll damage pump equipment and need to continue to buy expensive additives. (Last week wife came home with two bottles of Jacks Blue Magic that cost $90. Best that I could tell all that stuff was going to do was removes stains and dissolve calcium solids - there are none, water is sparkling clear) Anyway, I think the damage equipment story is sales pitch bunk. What do you think?

    Am I on right track w/drain/refill?

    Thanks for any/all comments.
    20,000 gal white plaster, w/spa waterfall, DE filter

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    Re: High CH and CYA - when to dump/refill h20?

    Welcome fellow North Texan!

    Yes, it looks like you are in line for a partial drain and fill. I had to do the same when I bought this house as the previous owners utilized a pool service that was in love with cal-hypo and trichlor. My CH was close to 700 ppm and my CYA was over 100 ppm.

    Yes, you need to go ahead and drain and refill and get that CH down (and your CYA down). It is better to do it in stages to be safe. Drop it a foot or two and then fill it up again. Retest, and then keep doing it until your get your numbers right. Once you get your CYA and CH under control, you will probably want to tackle your TA and get it down as well.

    Not sure where you are in North Texas, but it is a good idea to test your tap water or whatever source you are using to fill your pool with. Some areas around here do have fairly hard water and that is good to know ahead of time.

    High calcium can damage surfaces anad equipment so you know that you need to get it under control. You don't need expensive pool store chemicals to treat it though. Just do your drain and refills and get your CH under control.

    Otherwise, sounds like you are on the right track.
    10K gallon IG gunite with waterfall; Pentair CC320P filter; WhisperFlo 2 HP pump
    TF Test Kits - Pool Math - Pool School
    "It depends."- JohnT

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    Re: High CH and CYA - when to dump/refill h20?

    One more thing...I didn't see a pH in your numbers. You need to make sure that you are keeping it between 7.2 and 7.8. It should never be out of that range.

    As for your FC, it is too low for your CYA. A CYA of 100 ppm needs a minimum of 7 ppm FC to sanitize. Your water may look okay now but you are at risk of getting green water with it at 4.5 ppm.
    10K gallon IG gunite with waterfall; Pentair CC320P filter; WhisperFlo 2 HP pump
    TF Test Kits - Pool Math - Pool School
    "It depends."- JohnT

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    Re: High CH and CYA - when to dump/refill h20?

    I notice you stated that you will use up your pucks before you change to using the BBB method. If you do decide to do the partial drain and refill, then please stop using the pucks, immediately. You will just have your CYA back up way too high and rather quickly. Save your pucks to use while you are going to be away on vacation or something - they have a long shelf life. But continued regular use of pucks will get you right back to where you currently are.
    Buggs

    14,000 gallon, in ground, plaster, free form, play pool.
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    reebok's Avatar
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    Re: High CH and CYA - when to dump/refill h20?

    my .02 cents is drain to get your cya around 50-70 (50 is highest recommended by this site for non-salt water generator pools, but I run 70 which is manageable and being in texas a bit more cya than 50 won't hurt.) whatever your CH falls to, that's great, but I wouldn't base my drain on that. my CH is also over 600, you just have to keep the ph in check which is easy, especially when your water is balanced correctly.
    16x32 21,000 gallon in-ground exposed aggregate, 1.5hp pump, 120 sqft catridge filter, birdcage, solar panels, aquavac tigershark qc robot.

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    Re: High CH and CYA - when to dump/refill h20?

    Thanks all for the replies.

    I noticed one of the reply posts was from Flower Mound. How about that, that's where we landed, just south of 407.

    pH is 7.5 and I'll look into raising the FC to adjust to the CYA level we're currently at ...seems I saw a chart either in the test kit or on this site...

    that was a good idea about using the pucks when going on vacation....I'll start bleaching tomorrow...and I'll take the pool level down a foot or so tomorrow to start the refill process....time to backwash anyway...

    Thanks!
    20,000 gal white plaster, w/spa waterfall, DE filter

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    Re: High CH and CYA - when to dump/refill h20?

    Not sure where you are in North Texas, but it is a good idea to test your tap water or whatever source you are using to fill your pool with. Some areas around here do have fairly hard water and that is good to know ahead of time.
    great point...I did check the tap water today ...CH was 120 ...
    20,000 gal white plaster, w/spa waterfall, DE filter

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    dmanb2b's Avatar
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    Re: High CH and CYA - when to dump/refill h20?

    Quote Originally Posted by jkbk223
    I noticed one of the reply posts was from Flower Mound. How about that, that's where we landed, just south of 407.

    FYI, you can PM 257WbyMag...that was the other post from Flower Mound


    Good luck with the pool and welcome to TFP
    24'x52" AGP (13,500 Gallons), Intex SWG, (2)Solar Bear 4x20 panels, Hayward S220T Filter, 1/2hp Pentair Superflo

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    Re: High CH and CYA - when to dump/refill h20?

    jk,

    A belated welcome to the forum. That you haven't had water clarity issues is a good testament to you paying attention to your pool. With CYA that high, many of us experience algae blooms, etc.

    Repeating what everyone has already said, you are very wise to do a partial drain/refill. A target of 50 for the CYA would be good but, as reebok said, a tad more in Texas won't hurt.

    Once you get your CYA more manageable, (although you seem to have done fine to date) you will probably experience less chlorine consumption and certainly make it far easier to shock your pool should the need arise.

    Lugging the jugs of bleach will be a little bit aggravating but, honestly, bleach is simply the very best way you can keep chlorine in your pool.
    Dave S. - Forum owner
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
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    reebok's Avatar
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    Re: High CH and CYA - when to dump/refill h20?

    Quote Originally Posted by jkbk223
    pH is 7.5 and I'll look into raising the FC to adjust to the CYA level we're currently at ...seems I saw a chart either in the test kit or on this site...
    the main chart is in pool school here pool-school/chlorine_cya_chart_shock but this post goes up to 120 which is more applicable for you chlorine-cya-chart-t2346.html
    also, I believe http://www.thepoolcalculator.com should give you correct FC ranges no matter what cya level you enter.
    16x32 21,000 gallon in-ground exposed aggregate, 1.5hp pump, 120 sqft catridge filter, birdcage, solar panels, aquavac tigershark qc robot.

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