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Thread: Why different CYA Targets?

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    Why different CYA Targets?

    I see the standard recommendation for pools being chlorinated "by hand" - manual additions of some type of liquid chlorine seems to be 50, though I've seen posts here giving that a range of 30-50 depending...
    I also see that the recommended level with a salt system is a bit higher than that, 70-80 seems to come up a lot.

    That's a pretty big difference - I'm wondering why?

    I get that a salt system is a much more continuous process and _should_ maintain a more stable FC value, where a manual process is going to see a spike after the addition and a decline until the next addition. But in practice the salt system only gets run a few hours a day and the result is similarly uneven.

    Anybody have a good explanation for the discrepancy?

    -Denny
    IG gunite 20k Gal (estimate), Nautilus NS-60 filter (D.E.), Single speed pump (unreadable nameplate - assume 1HP) on a crappy mechanical timer.
    And a worn-out Kreepy Kraully. TF-100.

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    Mod Squad jblizzle's Avatar
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    Re: Why different CYA Targets?

    This has been answered many times over the years. The SWG adds FC very slowly and can benefit from the added protection from the sun. This also allows SWG to need to run less and prolong its life. The higher CYA is a balance between these benefits and the higher FC levels needed if a SLAM is required.
    Jason, TFP Moderator
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    Re: Why different CYA Targets?

    The range of 30-50 is so you have a ballpark for what you want to target based on the amount of sunshine you get and your pool water temp. For AZ, I'd suggest your target should be 50. I'm running my SWG 12 hours /day now--just a tad over a few. And it keeps my FC replenished to my daily usage.
    Pool size: 24000gal inground Vinyl-Taylor k-2006 and k-1766 test kits and-speed stir
    Intermatic P1353ME digital timer w/freeze sensor
    CircuPool Si-45 SWCG System
    Polaris 280 vacuum/Polaris PB4-60 boost pump
    Pentair IntelliFlo VS 3hp Pump--Pentair sand filter

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    Re: Why different CYA Targets?

    Quote Originally Posted by jblizzle View Post
    The higher CYA is a balance between these benefits and the higher FC levels needed if a SLAM is required.
    Ok, that makes a bit more sense as a risk/reward balance. On the risk side, needing to SLAM at the higher CYA levels takes _much_ more chlorine. But an automated chlorine system is less likely to "miss a day" and start a algae bloom. On the reward side there's less overall chlorine demand with the higher CYA level.

    -Denny
    IG gunite 20k Gal (estimate), Nautilus NS-60 filter (D.E.), Single speed pump (unreadable nameplate - assume 1HP) on a crappy mechanical timer.
    And a worn-out Kreepy Kraully. TF-100.

  5. Back To Top    #5
    Mod Squad jblizzle's Avatar
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    Re: Why different CYA Targets?

    Yup, that is a good summary.
    Jason, TFP Moderator
    18k IG pebblesheen pool, Hayward ProLogic P4 w/ T-15 SWG, Pentair 1HP 2-speed Superflo, Hayward 6020 DE filter
    500 sqft Heliocol solar panels, ThePoolCleaner, TF-100 test kit w/ SpeedStir
    Pool School + Test Kit + PoolMath = A TROUBLE FREE POOL
    If you found TFP helpful and we saved you money ... Become a TFP Supporter!

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