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Thread: CYA is gone, how to procede

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    CYA is gone, how to procede

    I opened my pool on Sunday. Water was cloudy, green floor. I ran out of bleach at the end of the season last year, and covered it on the onset of an algae attack. Figured smothering the growth without sunlight for several months would keep it at bay. Thought wrong?

    Anyhow, I shocked the snot out of it with bleach. I've been using TFP method for several years now. I'm comfortable with all my numbers, except CYA. Initially my CYA was very high, as I was converting from 3" tabs. I got it down to around 50 ppm, where it has been for several years, drifting down ever so slowly to I estimated it at about 45ppm exactly one year ago. (I only test at the beginning of the season as my understanding is only splash out decreases your number).

    Anyway, I've noticed my chlorine dropped rapidly after shocking, and even though I start each day with around 6ppm, it's down to 2.5-3 at the end of the day. That's much faster usage than I'm used to. I don't have a solar cover yet this year, but I didn't think it protected chlorine that much anyhow. Retested CYA finally this morning and I was able to fill the cylinder and still see the black dot. I'm assuming it is all gone.

    I've read that ammonia consumes CYA? I haven't had enough time to research this, but would like to get this resolved ASAP, as I'm using 2x the bleach as usual without any CYA protecting my FCs.



    A side note, if it sounds like I'm being a bit carefree with my chemistry, it is because I am. Not because I want to, but I currently have 5 kids 5 and under, and I'm preoccupied keeping the wife happy. Me fiddling with pool tests all day doesn't help her take care of the children. (Twin girls are 7 months old and a handlful right now) I have NOT run a full test this year, but everything has been stable until the CYA took a nose dive. PH is about 7.3 also. Please forgive me for being careless, I'm trying to do my job with the pool, without spending too much time there.
    14,000 gallon rectangle vinyl pool. 4' depth throughout
    Hayward SP2605x7 3/4 HP pump and S-220T sand filter (23 GPM filter rate) with SP0714T multi-port valve.
    Inline chlorinator
    T104R pump timer

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    Mr Bruce's Avatar
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    Re: CYA is gone, how to procede

    If you are only losing 3ppm / day that's not ammonia. That's normal. I'd add enough CYA to get to 20, and then SLAM until clear.
    32K gallon Plaster - 1hp Hayward 2 speed Super Pump - Hayward S200 Sand Filter - TF100XL
    Test Kits - Pool Math - Chlorine/CYA/Target/Slam Chart

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    Mod Squad JVTrain's Avatar
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    Re: CYA is gone, how to procede

    It's very common to lose all your CYA over the winter if the pool is not closed at shock level FC and covered. A few types of soil bacteria are thought to be able to consume CYA when they get into an unsanitized pool. They will convert your CYA into ammonia and other nitrogent biproducts. Ammonia creates a VERY high chlorine demand when you start to deal with it so that makes sense based on your description. You've gotten passed the ammonia with your initial bleach shocking, but the CYA is still gone.

    You now need to get CYA in your pool to moderate the strength of your FC and protect it from sunlight.
    Joel - TFP Moderator - Minnesota - **Become a TFP Supporter!** Helpful Links: ABCs of Pool Water Chemistry - SLAM Procedure - Chlorine/CYA Chart
    40x20 Pool: 32K Gallons * Vinyl * Bleach Chlorination * Hayward S270T Sand Filter * Pentair SuperFlo 1 HP * Teledyne/Laars Heater * AquaVac Tigershark * TF-100 w/ SpeedStir
    Isolated Spa - 345 Gallons

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    Re: CYA is gone, how to procede

    Also, you loose a little CYA whenever you backwash and over a very long period of time, CYA will degrade. It doesn't degrade quickly, but if you only check once a year, then you are not testing frequently enough. You should test CYA every 2 months... more often if you notice it dropping faster due to splash out and backwashing.

    The key to opening to clear water is close the pool whenever the water gets and stays below 60 degrees, bring FC to shock level for your CYA. Open before the pool reaches 60 degrees.
    Karen
    33K IG w spa plaster, Pentair 1HP Whisperflo, DE Filter, SWG CircuPool RJ-60, Dolphin Triton Plus, Raypak Dig 336K BTU, TF-100.
    Pool Math Chlorine / CYA Chart SLAM - Shock Level And Maintain
    2017 replaster/retile

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    Re: CYA is gone, how to procede

    Hey, thanks for the quick replies guys. Sounds like I need to calm down and go buy some stabilizer. (CYA, right?)

    Clorox Pool and Spa Chlorine Stabilizer, 4 lbs - Walmart.com

    Local Walmart shows this in stock, this should do the trick right? (edit: Just checked same product on Lowes website, you can zoom in on the label as it is 100% Cyanuric Acid) I'll grab some after work. 4 lbs is about what I need to get to 40 PPM, I'll add that and retest after several days. I'll let you know how it goes.
    14,000 gallon rectangle vinyl pool. 4' depth throughout
    Hayward SP2605x7 3/4 HP pump and S-220T sand filter (23 GPM filter rate) with SP0714T multi-port valve.
    Inline chlorinator
    T104R pump timer

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    Re: CYA is gone, how to procede

    Make sure to put it in a sock or panty hose and hang it in front a return. Squeeze it a few times a day.

    Karen
    33K IG w spa plaster, Pentair 1HP Whisperflo, DE Filter, SWG CircuPool RJ-60, Dolphin Triton Plus, Raypak Dig 336K BTU, TF-100.
    Pool Math Chlorine / CYA Chart SLAM - Shock Level And Maintain
    2017 replaster/retile

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    Re: CYA is gone, how to procede

    Thanks too for the correction. I filled a pair of loser single socks and dropped 'em in the skimmer after dinner. Having read your suggestion, I hooked the socks off a couple of clothes hangers and positioned them in front of two returns, and the CYA can be seen clouding through the sock! Wee!

    Clothes hangers and umbrella bases are a formidable duo.

    Anyhow, 4 lbs went in. It's interesting to see the mantra in Walmart changing. You guys are making a difference. I've never seen liquid chlorine in the pool section before, now they carry 10% for $2.50. They also carry big bags baking soda back in the pool section. Kind of a side topic, but it's been my experience that WITH pure bleach, you don't need baking soda. My PH drifts UP, and I need acid to counter act it. Perhaps that's why you've adjusted from the 'BBB' label.

    Speaking of acid, Pool calc suggests that the CYA will make my PH drop over 6 tenths, should I proactively fight that? Or just wait it out and test the pool tomorrow?
    14,000 gallon rectangle vinyl pool. 4' depth throughout
    Hayward SP2605x7 3/4 HP pump and S-220T sand filter (23 GPM filter rate) with SP0714T multi-port valve.
    Inline chlorinator
    T104R pump timer

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    Texas Splash's Avatar
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    Re: CYA is gone, how to procede

    I would give the stabilizer a good 24 hours to mix really well then re-test everything and you should be fine.
    Pat (a.k.a. Texas Splash) ~ My Pool: Viking Fiberglass; 17,888 Gal; Waterway Supreme 2-sp/2-hp pump; Hayward Ctg filter; TF-100 w/ Speed Stir
    Vital Links: POOL SCHOOL, RECOMMENDED LEVELS, RECOMMENDED CHEMICALS, Poolmath Calculator, SLAM, Chlorine/CYA CHART.
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