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Thread: cya: forum vs. manual

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    cya: forum vs. manual

    hi all,
    FC: 3
    CC: 0
    PH: 7.8
    TA: 70
    CH: 350
    CYA: 40 was wondering what you think about the different recommended levels for CYA. my Pentair manual says 30-50. but TFP says 70-90. any thoughts are appreciated.



    17,500 gal; intellichlor IC40; whisperflow 2-speed; CC200 cartridge filter; wet edge Antigua plaster
    17,000 gal. in ground, poured Jan. '13
    Pentair 200 CC filter
    plaster finish - wet edge Antigua
    Pentair whisperflow 1.5 hp. 2 speed pump
    Pentair IC20 swg

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    Re: cya: forum vs. manual

    70-90 is much better for a swg. It won't have to work as much extending its life. The recommendations here are tested tried and true. They frequently conflict with "common knowledge in the pool industry". I trust my trouble free pool to these specs. That's why it stays trouble free.
    18x36 inground vinyl lined, Hayward sand filter and tablet chrolinator, approx 18k gallon

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    linen's Avatar
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    Re: cya: forum vs. manual

    I agree with spidey's assessment.

    In addition, the cynic in me wonders if the manufacturer does know something about cya effects and wants to sell you a new cell sooner since running at 40 ppm cya will typically mean shorter cell life (more hours sooner) than running at 70-80 ppm cya.
    TFP Expert who uses Pool School and my TF100 test kit along with PoolMath for my: Round 11K gallon AGP with deep end, 20" sand filter, Matrix 1hp 2spd, 6 2ftX20ft solar panels (and solar cover!), Intex SWCG (copper bars disconnected) and a Rubadub hot tub (chlorine). The SLAM process is not finished until: 1. CC < 0.5 ppm, 2. An OCLT < 1.0 ppm and, 3. The water is crystal clear.

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    Re: cya: forum vs. manual

    thanks for the insight folks...i'll be adding more cya tomorrow. by the way, does anyone remember the ratio for the FC to CYA in percent, I saw it somewhere on this site...from chemgeek perhaps? thanks again
    17,000 gal. in ground, poured Jan. '13
    Pentair 200 CC filter
    plaster finish - wet edge Antigua
    Pentair whisperflow 1.5 hp. 2 speed pump
    Pentair IC20 swg

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    linen's Avatar
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    Re: cya: forum vs. manual

    For a swg you want to maintain a minimum FC level of 4.5% of your cya level. See: http://www.troublefreepool.com/chlor...art-t2346.html
    TFP Expert who uses Pool School and my TF100 test kit along with PoolMath for my: Round 11K gallon AGP with deep end, 20" sand filter, Matrix 1hp 2spd, 6 2ftX20ft solar panels (and solar cover!), Intex SWCG (copper bars disconnected) and a Rubadub hot tub (chlorine). The SLAM process is not finished until: 1. CC < 0.5 ppm, 2. An OCLT < 1.0 ppm and, 3. The water is crystal clear.

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    Re: cya: forum vs. manual

    Quote Originally Posted by staberg
    but TFP says 70-90
    The Recommended Levels for SWG says 70-80 and Water Balance for SWGs says between 70 and 80. Neither says 90.

    Most SWG manufacturers say something like 60-80 with 70-80 "ideal" or "best". Pentair seems to be the outlier. The reason for the higher CYA recommendation is that most SWG systems tend to be undersized and would not be able to output enough with the loss of chlorine from sunlight. Even if you purchased an over-sized unit to keep up, the greater SWG output will usually lead to a greater rise in pH, possibly due to both greater aeration from the hydrogen gas bubbles and from undissolved chlorine gas outgassing. Minimizing the SWG output by lowering chlorine loss via higher CYA therefore makes sense.

    Though you could go by the 4.5% rule, the Chlorine/CYA Chart is easier to use and a little more conservative (rounding up -- 5% with 4 ppm FC at 80 ppm CYA).
    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
    12 Fafco solar panels; Purex Triton PowerMax 250 natural gas heater (200,000 BTU/hr output); automatic electric pool safety cover; 4-wheel pressure-side "The Pool Cleaner"

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    Re: cya: forum vs. manual

    Hmmm. The difference in "Recommended Levels" and the implied recommended levels for SWG pools in the "Chlorine/CYA Chart" never registered with me until now. Perhaps the table for SWG pools in the "Chlorine/CYA Chart" should be changed, eliminating the levels for CYA of 60, and leaving just those for 70 & 80. That could eliminate a possible source of some minor confusion.
    "The early bird might get the worm, but its the second mouse that gets the cheese." ~ W. Rian Adams
    .
    Relative's IG Vinyl | 16x32 | ~18,600 gals | Hayward 3/4hp Pump | Hayward S244T Filter | Pentair Model 300 Chlorinator (not used) | Polaris 180

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    Re: cya: forum vs. manual

    Perhaps the table for SWG pools in the "Chlorine/CYA Chart" should be changed, eliminating the levels for CYA of 60, and leaving just those for 70 & 80. That could eliminate a possible source of some minor confusion.
    With an accuracy of plus or minus 10 ppm (CYA test) at best, 60-80 works fine for an swg pool. 70 can be considered a "sweet spot" but there are many pools managed successfully by using the 60-80 range.

    90 ppm is not a TFP recommendation for all the reasons that have been hashed over here on the forum for years.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

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