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Thread: loss to evaporation?

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    loss to evaporation?

    Florida had it's first few really hot days the last few days and my pool lost almost a foot of water over those two days.

    I think it has to be because of evaporation, as the pool has been full of water for over a month at or near the full level and I'd barely lost more than an inch or two in that time. I don't think I could have a leak and there's no wet spots around the pool to indicate a cracked pipe. Pool water is currently 81 degrees. Could it really have evaporated 6 inches a day in 85+ degree heat with direct sunlight and no cover?

    Is there any way to keep this from happening? Perhaps a chemical to put in or a cover of some kind?

    Thanks guys!

    Denis
    Clearwater, Florida

    12,000 gallon kidney shaped gunite pool
    Pentair Whisperflo 3/4HP Pump
    Pentair CCP420 420sq/ft Cartridge Filter
    Pentair Intellibrite 5G 120V Pool Light

  2. Back To Top    #2
    Mod Squad zea3's Avatar
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    Re: loss to evaporation?

    Hmmm... I would do a bucket test before writing off the loss to evaporation. Did you have this rate of evaporation last summer?
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    JasonLion's Avatar
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    Re: loss to evaporation?

    A foot of water in two days is more water loss than I have every heard of happening due to evaporation. Extreme evaporation rates in unusually dry/hot conditions are typically less than 1/2 inch per day.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
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    Re: loss to evaporation?

    I too would be suspicious of a leak given what you have told us. Do the bucket test to be certain.

    Linky pool-school/leak_detection
    10K gallon IG gunite with waterfall; Pentair CC320P filter; WhisperFlo 2 HP pump
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    Re: loss to evaporation?

    Currently I have a leak that only shows itself when the water table is low. I was losing 1-2 inches per day, then we got some heavy rains and the leak stopped. Now that its been dry again, the leak is starting back at about 1/2" per day. The leak was found to be around where the drain meets the plaster and the guy is supposed to come out today in his scuba gear to fix it. We had the same problem with the spa.
    25' x 13' Roman, 12000 gal IGP, Plaster, with 500 gal Spa
    SWG, 1 HP Max Flo Pump, C-900 cartridge filter
    Solar heat

  6. Back To Top    #6

    Re: loss to evaporation?

    The phantom leak has returned. After this post nearly a month ago, I filled the pool back up to the middle of the skimmer mouth. I've been using the pool every day and the water level always stays about the same. I thought the leak had disappeared.

    Then, this morning, it's back. I swam in the pool last night and when I got out, it was right at the same mid-skimmer-mouth level it always is. This morning (about 12 hours later), I let the dogs out and I was down almost 8" from the night before!

    I turned the equipment off for the day to see if it continues to lose water. This is so strange!

    Denis
    Clearwater, Florida

    12,000 gallon kidney shaped gunite pool
    Pentair Whisperflo 3/4HP Pump
    Pentair CCP420 420sq/ft Cartridge Filter
    Pentair Intellibrite 5G 120V Pool Light

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    frustratedpoolmom's Avatar
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    Re: loss to evaporation?

    Very strange...
    Helpful links: Pool School; CYA/Chlorine Chart
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    Re: loss to evaporation?

    During extended (all summer) 90 to 100+ days, "medium" humidity, with no splash out (no dogs or people using the pool) we usually have about 1" evaporation a day (hardly ever less than that); more loss with splash out. If it is over 2" I begin to suspect something else going on. During times when air temps stay 100+ for days to weeks more than 1" and humidity is a little lower usually (not as low as say Arizona but lower than many parts of the country). It's really hard to judge when there is a lot of splash out, but again, over 2" and I would start looking for another cause. We have a lot of wind year round that adds to evaporation.

    Our humidity averages between 50-60 during daytime year round; on the lower end during summer.

    Interesting website with average relative humidity for many cities in US.

    http://www.cityrating.com/relativehumidity.asp

    gg=alice
    1981, 25K, IG, Blue Plaster 1996, somewhat oval, widens a bit at shallow end, 1.5" pipes, 2" at Pad, 1 separate main drain, 1 skimmer, 4 returns + dedicated cleaner return, 10 ft deep end with very fast decline from shallow, Pentair Quad 80 DE, Pentair Intelliflo VF, 3/4 HP Booster Pump (equipment pad about 8 ft below top of pool), Challanger 3/4 Trash/Emergency Pump 120v, Polaris 280 (pressure), iRobot Verro cleaner (robotic), Aquabot Turbo (robotic), Jacuzzi Tracker 4X (vacuum) Pool Blaster (Buster), Two (2) PoolSkims, Solar Breeze (solar powered top skimmer) (beta to ver. 2, release date 2010), ColorSplash LED replacement bulb. Aries 550 gal separate spa, 2002 (our 3rd and BEST spa) , BBB-Bromine

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    Re: loss to evaporation?

    At this point, whatever is causing it to drain is still in action. Of course, I can't see bottom right now because of the dirt. I'll see how much of that I can get cleaned up and start doing leak tests.
    Clearwater, Florida

    12,000 gallon kidney shaped gunite pool
    Pentair Whisperflo 3/4HP Pump
    Pentair CCP420 420sq/ft Cartridge Filter
    Pentair Intellibrite 5G 120V Pool Light

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    Join Date
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    Re: loss to evaporation?

    Do you get more loss with the pump on, off, or about the same either way?
    14,000 gallon IG, Vinyl. Hayward 3/4 hp superpump, Penatair IC40 SWCG, Pentair automation, Hayward sand filter, Aqua Comfort heat pump, Hayward 400k Lo-Nox LP heater.

  11. Back To Top    #11

    Re: loss to evaporation?

    Quote Originally Posted by bk406
    Do you get more loss with the pump on, off, or about the same either way?
    It looks about the same both ways. I've had the pump off now for 2 days and I've lost around 8" each day. There's definitely got to be a leak somewhere.
    Clearwater, Florida

    12,000 gallon kidney shaped gunite pool
    Pentair Whisperflo 3/4HP Pump
    Pentair CCP420 420sq/ft Cartridge Filter
    Pentair Intellibrite 5G 120V Pool Light

  12. Back To Top    #12

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    Re: loss to evaporation?

    /it's most likely not in the plumbing. Do you have a pool light? Pool is vinyl?
    14,000 gallon IG, Vinyl. Hayward 3/4 hp superpump, Penatair IC40 SWCG, Pentair automation, Hayward sand filter, Aqua Comfort heat pump, Hayward 400k Lo-Nox LP heater.

  13. Back To Top    #13

    Re: loss to evaporation?

    Pool is concrete/gunite. Pool light is installed and working, but the water level is now at the pool light and still dropping.
    Clearwater, Florida

    12,000 gallon kidney shaped gunite pool
    Pentair Whisperflo 3/4HP Pump
    Pentair CCP420 420sq/ft Cartridge Filter
    Pentair Intellibrite 5G 120V Pool Light

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    Melt In The Sun's Avatar
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    Re: loss to evaporation?

    Well, the leak can only be in one of a few places. If the water level is at the light, it's below skimmers and all returns I presume? Do you have a main drain? Any other pipes like a cleaner/suction return? The pump is currently off? I suppose there could be a leak in the pool shell itself, but that is pretty rare.
    11,200 gal, Pebble-Tec; Tristar 2-speed 1hp - Swimclear 325 ft2 cart - SWG - A & A in-floor cleaner - Heat pump. For the poolside cooking, a Yoder Wichita and a Big Steel Keg!
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    Melt In The Sun's Avatar
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    Re: loss to evaporation?

    Looking again at your first thread here, I see you do have a main drain. If the water level in your first picture is where it equalizes (below the light and all other holes in the shell), your leak is probably there.
    11,200 gal, Pebble-Tec; Tristar 2-speed 1hp - Swimclear 325 ft2 cart - SWG - A & A in-floor cleaner - Heat pump. For the poolside cooking, a Yoder Wichita and a Big Steel Keg!
    TF Test Kits -- PoolMath -- Pool School
    Make each day your masterpiece. - John Wooden

  16. Back To Top    #16

    Re: loss to evaporation?

    Quote Originally Posted by Melt In The Sun
    Looking again at your first thread here, I see you do have a main drain. If the water level in your first picture is where it equalizes (below the light and all other holes in the shell), your leak is probably there.
    That's what I'm thinking. I was going to let it continue draining so I have less water to deal with when I'm cleaning the dirt out of the pool. Hopefully it stops leaking at some point so I can take a stab at whereever the problem it.
    Clearwater, Florida

    12,000 gallon kidney shaped gunite pool
    Pentair Whisperflo 3/4HP Pump
    Pentair CCP420 420sq/ft Cartridge Filter
    Pentair Intellibrite 5G 120V Pool Light

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