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Thread: How much CYA loss

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    kywildcats's Avatar
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    How much CYA loss

    I'm sure it's here somewhere, but I can't find it in search.
    How much loss of CYA can be expected during rain, and evaporation loss in a weekly period?
    Mark
    20'x28' IG, Vinyl, (Sept 2015) 14,900 Gallon, 3'4 to 5'6 deep, SPLAPOOL 1.5 HP, 220v, 2 speed pump, Waterway Carefree 27" 400 LB Sand filter, Digital Nano plus SWG, TF-100 test kit /speed stir. Dolphin Primal x3 robotic cleaner

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    Mod Squad tim5055's Avatar
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    Re: How much CYA loss

    The natural,loss of CYA is minimal, maybe 1-2 ppm per month. Rain and evaporation will have no effect on the value unless you pump water (with CYA in solution) out of the pool.

    Now, with that being said changes in water level will cause the CYA to change, but most probably below the values we can see with our test. As an example, your pool,has a CYA of 50 and you have 2" of water evaporate. Technically because there is the same amount of CYA (CYA does not evaporate, it stays behind) in less water the CYA may go up, let's say to 52. But, as soon as you add the 2" of water back with your hose the CYA goes back to the original. 50 you had.

    Rain has the opposite effect, you start with 50 and get 2" of rain. You now have the original amount of CYA in a larger body of water, so the tested CYA level will go down slightly, let's say to 48. Now as the water evaporates the CYA will return to 50. But, if you pump 2" of water out while the level is high you now have a new baseline of 48.
    TFP Moderator 39 X 18 23,000(ish) freeform gunite; built 2007ish; Pentair Triton II TR100 600lb Sand filter; 2 HP Pentair pump with 2.2 HP AO Smith single speed motor; 2 skimmers, 1 main drain, 4 returns w/waterfall, Stenner 45MHP2 3GPD running@ 60% - 15 gal Tank; heated by the sun CYA 200+ when I started - 50 now. Dolphin Supreme M5 Pool Cleaner. Hot Springs SX Spa, 285 gallon

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    kywildcats's Avatar
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    Re: How much CYA loss

    I did backwash this afternoon longer than usual. I knew lots of rain was coming tonight and tomorrow.
    I was just getting to the level of cya I wanted. I guess I pumped some out.
    Mark
    20'x28' IG, Vinyl, (Sept 2015) 14,900 Gallon, 3'4 to 5'6 deep, SPLAPOOL 1.5 HP, 220v, 2 speed pump, Waterway Carefree 27" 400 LB Sand filter, Digital Nano plus SWG, TF-100 test kit /speed stir. Dolphin Primal x3 robotic cleaner

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    Mod Squad tim5055's Avatar
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    Re: How much CYA loss

    Quote Originally Posted by kywildcats View Post
    I did backwash this afternoon longer than usual. I knew lots of rain was coming tonight and tomorrow.
    I was just getting to the level of cya I wanted. I guess I pumped some out.
    Some, yes. But as someone who needed to go from a CYA level,of 250 down to something more reasonable I can assure you that unless you pumped out lots of water you didn't change your CYA by much.
    TFP Moderator 39 X 18 23,000(ish) freeform gunite; built 2007ish; Pentair Triton II TR100 600lb Sand filter; 2 HP Pentair pump with 2.2 HP AO Smith single speed motor; 2 skimmers, 1 main drain, 4 returns w/waterfall, Stenner 45MHP2 3GPD running@ 60% - 15 gal Tank; heated by the sun CYA 200+ when I started - 50 now. Dolphin Supreme M5 Pool Cleaner. Hot Springs SX Spa, 285 gallon

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    kywildcats's Avatar
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    Re: How much CYA loss

    Thanks Tim. I pumped out a inch or inch and half of water today. Don't guess that hurt too much.
    Mark
    20'x28' IG, Vinyl, (Sept 2015) 14,900 Gallon, 3'4 to 5'6 deep, SPLAPOOL 1.5 HP, 220v, 2 speed pump, Waterway Carefree 27" 400 LB Sand filter, Digital Nano plus SWG, TF-100 test kit /speed stir. Dolphin Primal x3 robotic cleaner

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    Frankhugus's Avatar
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    Re: How much CYA loss

    Quote Originally Posted by tim5055 View Post
    Some, yes. But as someone who needed to go from a CYA level,of 250 down to something more reasonable I can assure you that unless you pumped out lots of water you didn't change your CYA by much.
    This is depressing! I'm where you were and can't drain. Thank you Leslie's.
    14,000 Gal, InGround, Spa Attached, Satin-Matrix Northshore Tahoe Pebble-Tec, Remodel 6/15, Taylor K-2006 Kit, Pentair IntelliFlo Variable Speed Pump, Polaris 280 Sweep, Jandy CL460 Cartridge Filter, Solar Heated. Taylor K-2006 Test Kit

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