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Thread: CYA Problem URGENT

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    CYA Problem URGENT

    Hi guys some questions id like to ask, test results below:
    - Can high CYA like 70 ppm cloud pool water?
    - Do you think i should shock with MPS?
    - Should i also add algecide to pool whilst shocking with MPS? How much MPS should i use?
    - Any other recommendations for treatment?

    THanks a 1000

    Test Conditions as such:
    Water Clarity: Dull
    Temp: 30 C
    pH: 7.5
    TA: 80
    CAL: 140

    FCL: 2.6
    TCL: 2.9
    CYA: 70

    Fe: 0
    Cu: 0

    Pool Size: 20,000 gallons
    27,500gal IG plaster that needs recoating/painting!, Pentair Whisper-flo 1hp 2 speed, 48sf DE, Pentair Legend II pressure-side cleaner, BBB newbie

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    Re: CYA Problem URGENT

    Oh and btw if i do a bucket test and find a Cl Demand needing say 50 ppm FCL, can i add at smaller doses and maintain my Cl @ 6 - 7 ppm for extended periods instead of shocking?
    27,500gal IG plaster that needs recoating/painting!, Pentair Whisper-flo 1hp 2 speed, 48sf DE, Pentair Legend II pressure-side cleaner, BBB newbie

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    reebok's Avatar
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    Re: CYA Problem URGENT

    cya of 70 is high (assuming no swg) but not unmanageable. mine is 70. mps isn't recommended. algaecide isn't recommended. yes, see pool school, there's a lot of good information there that will help you. after you read it a couple times, ask more questions if you have them. also, you need a good test kit. pool-school/
    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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    JasonLion's Avatar
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    Re: CYA Problem URGENT

    With CYA of 70 you need to keep your FC level at 5 or higher at all times, otherwise algae can get started.

    You need to shock the pool, see this article at Pool School for instructions.

    No you can't maintain a lower FC level for a longer period of time. That won't kill the algae. If you had an ammonia problem that would work, but that isn't the problem you have.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
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    Re: CYA Problem URGENT

    - i dont understand why it isnt recommended to use Mono Persulphate besides that it is a chlorine reducer, doesnt it burn
    the organics?
    - if i feed Bromine and bring to shock lvl since iv got a very oversized feeder would it work good with Monopersulphate?
    at least the Bromine doesnt go into dead lock with the CYA?
    - lastly can i add Benzyl ammonium chloride?
    27,500gal IG plaster that needs recoating/painting!, Pentair Whisper-flo 1hp 2 speed, 48sf DE, Pentair Legend II pressure-side cleaner, BBB newbie

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    Re: CYA Problem URGENT

    sry so CYA in itself doesnt not cause a clarity issue?
    27,500gal IG plaster that needs recoating/painting!, Pentair Whisper-flo 1hp 2 speed, 48sf DE, Pentair Legend II pressure-side cleaner, BBB newbie

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    frustratedpoolmom's Avatar
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    Re: CYA Problem URGENT

    No. it doesn't, your clarity issue is because your chlorine level is too low.

    You need to shock the pool as Jason advised above. MPS is recommended for indoor pools.

    If you just follow the steps in the article Jason linked you will be fine.

    Just use chlorine, it's ALL YOU NEED.
    Helpful links: Pool School; CYA/Chlorine Chart
    24' round AG pool, 52" high, Raypak heater; Waterway 2 spd Pump;
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    Re: CYA Problem URGENT

    Sry just trying understand more about pools & spas:

    -So besides the cost factors is MPS plausible? Or should it only be used with Bromine?
    - What Cl levels are safe to swim with my CYA?
    27,500gal IG plaster that needs recoating/painting!, Pentair Whisper-flo 1hp 2 speed, 48sf DE, Pentair Legend II pressure-side cleaner, BBB newbie

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    JasonLion's Avatar
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    Re: CYA Problem URGENT

    The only serious "problem" with MPS is that it costs more than chlorine. In an outdoor pool chlorine is just as good or better in every way and costs less. MPS has some advantages for indoor pools. Also, MPS is an oxidizer but not a sanitizer. You have to use chlorine anyway, to have some sanitizer. It is much simpler to just use chlorine, rather than keep track of two different chemicals. Also, MPS will register on the test as CC, which makes it difficult to know what your CC level actually is.

    Bromine is not a good choice for an outdoor pool, since it can't be stabilized against sunlight. You end up losing all of your sanitizer each day.

    CYA is only a problem if the level is too low or too high. As long as you keep the CYA level in the appropriate range, CYA helps dramatically.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
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    frustratedpoolmom's Avatar
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    Re: CYA Problem URGENT

    Quote Originally Posted by aho.lwi
    - What Cl levels are safe to swim with my CYA?
    Anything above your "min" and up to "shock" level.
    Helpful links: Pool School; CYA/Chlorine Chart
    24' round AG pool, 52" high, Raypak heater; Waterway 2 spd Pump;
    150 Sq ft. Clearwater Cartridge Filter; Former and DISSATISFIED "Pool Frog" owner
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    Re: CYA Problem URGENT

    - So in other words MPS would and can cure an algae problem, what about h2O2 can they be considered same?
    - Iv still got around 25lbs of BCDMH left so you think it would be good as a short term replacement to my TCCA? besides
    i have no where else to use these tablets so....., but definately ill be switching to BBB method.
    - So are you saying FC of 8 or 14 would still be safe for me because of my CYA?
    27,500gal IG plaster that needs recoating/painting!, Pentair Whisper-flo 1hp 2 speed, 48sf DE, Pentair Legend II pressure-side cleaner, BBB newbie

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    frustratedpoolmom's Avatar
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    Re: CYA Problem URGENT

    [quote="aho.lwi"]- So in other words MPS would and can cure an algae problem, what about h2O2 can they be considered same?
    - Iv still got around 25lbs of BCDMH left so you think it would be good as a short term replacement to my TCCA? besides
    i have no where else to use these tablets so....., but definately ill be switching to BBB method.
    - So are you saying FC of 8 or 14 would still be safe for me because of my CYA?[/quote]

    Yes.

    (I'll let the REAL chemistry experts tackle your chem questions....)
    Helpful links: Pool School; CYA/Chlorine Chart
    24' round AG pool, 52" high, Raypak heater; Waterway 2 spd Pump;
    150 Sq ft. Clearwater Cartridge Filter; Former and DISSATISFIED "Pool Frog" owner
    http://www.PerfectlyClearPoolService.com

  13. Back To Top    #13

    Re: CYA Problem URGENT

    eagerly awaiting.
    27,500gal IG plaster that needs recoating/painting!, Pentair Whisper-flo 1hp 2 speed, 48sf DE, Pentair Legend II pressure-side cleaner, BBB newbie

  14. Back To Top    #14

    Re: CYA Problem URGENT

    is there anyone around that could give me some directions
    27,500gal IG plaster that needs recoating/painting!, Pentair Whisper-flo 1hp 2 speed, 48sf DE, Pentair Legend II pressure-side cleaner, BBB newbie

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    reebok's Avatar
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    Re: CYA Problem URGENT

    there are, just not this second perhaps. it's barely been an hour :)
    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: CYA Problem URGENT

    Quote Originally Posted by aho.lwi
    - So in other words MPS would and can cure an algae problem, what about h2O2 can they be considered same?
    - Iv still got around 25lbs of BCDMH left so you think it would be good as a short term replacement to my TCCA? besides
    i have no where else to use these tablets so....., but definately ill be switching to BBB method.
    - So are you saying FC of 8 or 14 would still be safe for me because of my CYA?
    MPS will not cure an algae problem. Though it oxidizes some organics, it does not kill algae as quickly as chlorine.

    H2O2 is hydrogen peroxide and is incompatible with chlorine (it will use up chlorine if you add it to the pool). Think of it as a chlorine neutralizer, so don't use it.

    BCDMH is for bromine. You do not use this in a chlorine pool. Once a pool has used this, it is stuck as a bromine pool for a very long time. If you had a spa, you could use the BCDMH for it. Since there is no protection of bromine from breakdown in sunlight, the bromine or chlorine demand in such a pool is high if it is outdoors exposed to sunlight (though your CYA does somewhat help protect the lower depths of water from such sunlight).

    Yes, an FC of 8 or 14 is safe for you assuming your CYA is at 70 ppm. The normal range would be an FC no lower than 5 ppm and usually not higher than 10 ppm though it can be 14 if need be (but you should be able to maintain a range such that you don't lose more than 50% FC per day -- and at a CYA of 70 ppm you should be able to lose only 20-40% per day).

    Richard
    16,000 gallon outdoor in-ground 16'x32' plaster pool; Pentair Intelliflo VF pump; Pentair IntelliTouch i9+3s control system; Jandy CL-340 square foot cartridge filter
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    Re: CYA Problem URGENT

    aho.lwi,

    What is the urgency of your situation?
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
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  18. Back To Top    #18

    Re: CYA Problem URGENT

    Thanks for the help guys.

    Last Few Question:

    - Since MPS and Hydrogen peroxide are both oxygen releasing why does one destroy Cl and the
    other doesnt?
    - So in other words MPS does kill algae just that it isnt fast like Cl?
    - So in other sodium percarbonate is no good for a Cl pool as well?
    27,500gal IG plaster that needs recoating/painting!, Pentair Whisper-flo 1hp 2 speed, 48sf DE, Pentair Legend II pressure-side cleaner, BBB newbie

  19. Back To Top    #19

    Re: CYA Problem URGENT

    -would it be better i just leave my Cl levels at 15 - 16 ppm rather than bring my FC to shock of 20 ppm for extended periods?
    - iv got two pool parties at my house one today and the next tmrw and so im wondering if i could just maintain higher doses of CL instead of shocking
    27,500gal IG plaster that needs recoating/painting!, Pentair Whisper-flo 1hp 2 speed, 48sf DE, Pentair Legend II pressure-side cleaner, BBB newbie

  20. Back To Top    #20

    Re: CYA Problem URGENT

    -Also im a little confused calclulator say Cl 20ppm for shock and chart says Cl 28ppm?
    27,500gal IG plaster that needs recoating/painting!, Pentair Whisper-flo 1hp 2 speed, 48sf DE, Pentair Legend II pressure-side cleaner, BBB newbie

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