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Thread: Evaporation???

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    guamguy's Avatar
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    Evaporation???

    OK, this may be a silly question, but here goes... I loose about an inch of water from my pool each day. The pool gets direct sunlight from 6:30am until 6:00pm. We live in Guam, which is at the 13th parallel, so our sunlight is more "direct" than in the continental US. I really hope I don't have a leak, I just got this house a month ago If I isolate the spa, it too looses about an inch of water per day. All my water tests such as CH and CYA have not changed with the addition of water every 2 days. Am I over-reacting by thinking I have a leak? I guess I can put on my scuba gear and grab a bottle of food coloring to check around the returns and main drain...
    12,800 gallon IG plaster kidney-shaped pool, waterslide, 800 gallon spa.
    1HP 2 speed Sta-Rite pool pump, 1.5 HP Sta-Rite spa jet pump. 2 skimmers, 1 main drain
    Purex-Triton TR-60 325 lb.sand filter. 2" Plumbing, Intex SWCG, TF-100 test kit.
    Link to pics of my pool! http://www.troublefreepool.com/my-oasis-t26558.html

  2. Back To Top    #2
    Guest

    Re: Evaporation???

    Do a bucket test first. Chances are you are just experiencing evaporation, and the bucket can confirm that. Switch to the dye test if the bucket test points to a leak, and maybe a pressure test after the dye to pin point it, if it turns out there really is a leak.

    Post back. I'm betting on evaporation!

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    Ohm_Boy's Avatar
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    Re: Evaporation???

    The trick here would be a "bucket test". Place a bucket of water in the pool so that it sticks out above the waterline, like maybe on the top step in the shallow end. Make a mark on the side of the bucket at the level of the water inside the bucket, and another mark at the level of the pool water. Next day, mark the levels again. Both inside and outside the bucket should lose to evaporation at the same rate, so if the pool level drops more than the bucket level, you have a leak.
    [center:1kpalu48]Helpful Links: Pool School | CYA/Chlorine Chart | Pool Calculator[/center:1kpalu48]

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    mas985's Avatar
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    Re: Evaporation???

    Even that far south, I wouldn't expect evaporation to be that high. Evaporation is proportional to the temperature difference of the water to the dew point temperature. Based upon Guam's current weather conditions, I wouldn't expect more than a 1/4" per day even with a 15 MPH wind.
    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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    guamguy's Avatar
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    Re: Evaporation???

    Sounds good, I'll try the bucket test tomorrow. Before we moved into the house, a pressure test was done on the pool and spa plumbing, and all was said to be good, but I did not witness the test . I know I have a leak from the mechanical seal on the spa pump (my fault in not properly educating the family ), but that is a very small leak. The overhaul kit is on it's way I'm just worried about a leak from around a return or the main drain... Hopefully the bucket test comes out good...If I can keep the kids from using the bucket as a pool toy
    12,800 gallon IG plaster kidney-shaped pool, waterslide, 800 gallon spa.
    1HP 2 speed Sta-Rite pool pump, 1.5 HP Sta-Rite spa jet pump. 2 skimmers, 1 main drain
    Purex-Triton TR-60 325 lb.sand filter. 2" Plumbing, Intex SWCG, TF-100 test kit.
    Link to pics of my pool! http://www.troublefreepool.com/my-oasis-t26558.html

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    Re: Evaporation???

    My pool can lose an inch a day with our extreme sun, heat, high winds, and even more loss with splash out from the dogs.

    I've had this pool going on 24 years and it is normal for my pool and weather conditions.

    And do the bucket test just to be sure.

    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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    AnnaK's Avatar
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    Re: Evaporation???

    Quote Originally Posted by simicrintz
    Switch to the dye test if the bucket test points to a leak, and maybe a pressure test after the dye to pin point it, if it turns out there really is a leak.

    Would you please go into more detail on the dye test and pressure test?

    I understand and know how to do the bucket test. If that were to point to a leak, how do you do the dye test? My understanding is, you squirt dye at a spot where you think the leak is and, if there is a leak, the dye gets sucked in. Correct? Doesn't that require a guy (or gal) to swim along with goggles and a snorkel scoping out the entire pool bottom for a possible breach in the liner? Or is there a different method?

    And then, how do you pinpoint a leak with the pressure test—and how do you do a pressure test?

    Sigh. Yeah, I think we may have a leak in our AGP so I'm trying to learn as much as I can.
    AnnaK

    12,500 gal AGP, Hayward sand filter, Pentair 2-speed pump, timer.
    Please visit our Pool Issues pages for information about step weights, managing the solar cover, and PoolSkim.

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    JasonLion's Avatar
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    Re: Evaporation???

    The dye test is just as you describe. Some people have rigged up dye bottles on the end of a pole, so they can squirt dye without being in the water, but generally it is easier to do from in the water.

    A pressure test checks the plumbing to see if the leak is in the plumbing. It requires you to plug all of the pipes going into or coming out of the pool and then pressurize the plumbing system and wait to see if it loses pressure. It is complicated enough and requires some special hardware, so most homeowners don't find it practical to do themselves, though it is possible.

    With an above ground pool you can usually find a leak by looking around for wet spots. The main time you would need a dye test is if you suspect a leak in the floor of the pool. Similarly, for an above ground pool, a pressure test probably won't find anything that looking for leaks wouldn't find. In ground pools require more complex techniques because most of the plumbing is underground.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

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    AnnaK's Avatar
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    Re: Evaporation???

    Given that all the plumbing to/from my system is visible I know I don't have a leak on the mechanical side.

    I do have a damp spot, something I noticed toward the end of last season and let go because of the time of year. It's back again. The thing is, I can't say with any certainty that the liner leak is in the vicinity of the spot because water has a way of finding the lowest level. The leak could be anywhere with the water simply flowing downhill.

    A friend has put some dye tabs in the mail to me and we'll try that as soon as the water is warm enough to get in and do a visual inspection and test of the seams. We lose approximately 1" every 36 hours. I'll know much better once we get the bucket test set up.

    Thanks for the explanations.
    AnnaK

    12,500 gal AGP, Hayward sand filter, Pentair 2-speed pump, timer.
    Please visit our Pool Issues pages for information about step weights, managing the solar cover, and PoolSkim.

  10. Back To Top    #10
    Ohm_Boy's Avatar
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    Re: Evaporation???

    I always just used a small squeeze/squirt bottle with food coloring in it. Puff out a little dye cloud around where you want to check, and watch for movement. The water does need to be very still to do a dye test. That means no pump, and be very still while in the water. You'll have to work kind of slowly.
    [center:1kpalu48]Helpful Links: Pool School | CYA/Chlorine Chart | Pool Calculator[/center:1kpalu48]

  11. Back To Top    #11

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    Re: Evaporation???

    As and FYI. As I said above, it is not unusual for my pool to lose 1" a day to evaporation from wind, sun, heat, and splash out. Yesterday was over cast all day, coolish, only slight wind, <20 mph, only one dog swam a few times without the others jumping in, and at end of day there was no perceptible loss of water.

    Over the years I've done the dye test using bottles of red food dye from grocery. The only problem I ever had was a leak in the light niche. That was were the leak was. With the light in place I couldn't get an indication of water being sucked in around the rim but after I took the light bucket out of the niche the dye made a bee-line for the leak. It was where the cord goes through the wall. That leak was causing nearly 12" loss of water in 24 hr period.

    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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    mas985's Avatar
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    Re: Evaporation???

    I would be concerned if the pool lost 1" per day with ONLY evaporation. With splashout, perhaps but with only evaporation, you would need a lot of wind and very very dry conditions. 1" is 2.5x the daily average in death valley and 4x the daily average for North Texas.
    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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    guamguy's Avatar
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    Re: Evaporation???

    Hi again, I tried the bucket test and all went well. It appears that the pool will only loose about 1/4 to 1/2 inch per day if the pool is not being used. The pool does get used everyday, and during the weekends it's in use all day and into the night. The kids do create quite a bit of splash-out, so all in all, I think I'm leak-free!
    12,800 gallon IG plaster kidney-shaped pool, waterslide, 800 gallon spa.
    1HP 2 speed Sta-Rite pool pump, 1.5 HP Sta-Rite spa jet pump. 2 skimmers, 1 main drain
    Purex-Triton TR-60 325 lb.sand filter. 2" Plumbing, Intex SWCG, TF-100 test kit.
    Link to pics of my pool! http://www.troublefreepool.com/my-oasis-t26558.html

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    Mod Squad Bama Rambler's Avatar
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    Re: Evaporation???

    That's good news. Our pool is also used almost daily and we can lose an inch a day with the GK's in there. They're splashy little creatures!
    Dave J. TFP Moderator
    24' x 52" Round AGP. 2hp/¼hp SPL Power-Flo 2-speed pump. 200sqft Waterway Cartridge Filter. 45MHP2(3GPD) Stenner Peristaltic Pump
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    Ohm_Boy's Avatar
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    Re: Evaporation???

    Yes, that is good news. Thanks for the update.
    [center:1kpalu48]Helpful Links: Pool School | CYA/Chlorine Chart | Pool Calculator[/center:1kpalu48]

  16. Back To Top    #16
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    Re: Evaporation???

    9 times out of 10 that is the case! Happy to hear you are normal

  17. Back To Top    #17
    guamguy's Avatar
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    Re: Evaporation???

    Yup, no leaks=no problems Gonna grab a beer or three and relax in the spa to celebrate
    12,800 gallon IG plaster kidney-shaped pool, waterslide, 800 gallon spa.
    1HP 2 speed Sta-Rite pool pump, 1.5 HP Sta-Rite spa jet pump. 2 skimmers, 1 main drain
    Purex-Triton TR-60 325 lb.sand filter. 2" Plumbing, Intex SWCG, TF-100 test kit.
    Link to pics of my pool! http://www.troublefreepool.com/my-oasis-t26558.html

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