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Thread: Summer Solstice

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    Summer Solstice

    Not sure if this is the place to post this thread, but here it goes:

    The summer solstice is fast approaching. This means (at least for us in the lower portion of the US) that during the 2 weeks before and the 2 weeks immediately after, we are peppered with a higher concentration of UV as the sun is closest to its zenith and at its zenith in our hemisphere at the Tropic of Cancer. July and August might be hotter, but less UV is actually reaching us (relatively speaking) as the sun is already moving back to the equator (I know, the earth is tilting; the sun is not actually moving).

    Should we expect higher FC loss during these next 4 weeks or is it a wash due to higher temperatures in the Jul/Aug? I know I'm probably worrying about the wrong thing, but it's an interesting topic and also one that should be kept in mind for sunscreen diligence.
    10,000 gal | In-Ground | White Plaster | Chlorine | Cartridge Filter | V-Green 165 VSP | Borated | Filled from City Water Source | TF-100 Test Kit | 4 Returns | 1 Suction Port | Jan 2016 Build

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    mas985's Avatar
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    Re: Summer Solstice

    The energy incident on the pool, across the entire spectrum, is proportional to the cosine of the angle of incidence off normal. So it really doesn't change that quickly and May 21st/Jul 21st is only about 2% lower than June 21st. Not much of a difference. It changes much faster near the equinox.
    Mark
    Hydraulics 101; Pump Ed 101; Pump/Pool Spreadsheets; Pump Run Time Study; DIY Acid Dosing; DIY Cover Roller
    18'x36' 20k plaster, MaxFlo SP2303VSP, Aqualogic PS8 SWCG, 420 sq-ft Cartridge, Solar, 6 jet spa, 1 HP jet pump, 400k BTU NG Heater

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    Mod Squad pooldv's Avatar
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    Re: Summer Solstice

    The amount of information available at TFP is astronomical!
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    Mod Squad JVTrain's Avatar
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    Re: Summer Solstice

    Quote Originally Posted by mas985 View Post
    The energy incident on the pool, across the entire spectrum, is proportional to the cosine of the angle of incidence off normal. So it really doesn't change that quickly and May 21st/Jul 21st is only about 2% lower than June 21st. Not much of a difference. It changes much faster near the equinox.
    *nightmares of sophomore geometry resurface ominously*
    Joel - TFP Moderator - Minnesota - **Become a TFP Supporter!** Helpful Links: ABCs of Pool Water Chemistry - SLAM Procedure - Chlorine/CYA Chart
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    Re: Summer Solstice

    Quote Originally Posted by pooldv View Post
    The amount of information available at TFP is astronomical!
    Isn't it tho? I wasn't sure where to post it, but I knew someone would find it!!!
    10,000 gal | In-Ground | White Plaster | Chlorine | Cartridge Filter | V-Green 165 VSP | Borated | Filled from City Water Source | TF-100 Test Kit | 4 Returns | 1 Suction Port | Jan 2016 Build

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