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Thread: Pool draining

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    Join Date
    Aug 2012
    Location
    Near Sacramento, CA
    Posts
    47

    Pool draining

    Hi,
    My brother's pool has a high level of calcium. I told him he has to drain his pool, but he said that he needed to know whether there is water underneath the pool since it will cause the pool to push out of the ground. Do you know where he would find that information? He's looked online and even called the local water people, but to no avail. Thanks! He lives in LA, specifically in the Westlake, Agoura Hills, area.
    Outdoor IG Plaster Pool @18,000 gallons
    Cartridge Filter: Jandy CL580 (filter area 580 ft2, Max Flow 150 gpm, 6-hr capacity 54,000g)
    Pool Built est. 2002

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    Join Date
    Dec 2012
    Location
    Manassas Park, VA
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    191

    Re: Pool draining

    I have been going through the same thing in Virginia and have not been able to find any one that can tell me the water table in my area. Even though I was told someone in the Parks department should be able to tell me. However I do know that my pool has two hydrostatic plugs on the bottom and hopefully a hydrostatic valve in one of the main drains.

    My understanding is that I can drain the pool and still have some time (hours) once it is empty to get them open before the pool would be lifted if that was a possibility. I imagine that the higher the water table the less time I would have to open the plugs. However I have no strong evidence that this is the case. So out of precaution I am trying to do this after about 10 straight days of no rain in hopes that this will dry the ground enough if there is an issue with the water table.

    I have also been told that if the house has an inground basement that there should not be an issue with the water table unless the pool is deeper than the basement.
    25,000 gallon in ground white plaster- 1 1/2 HP Pentair SuperFlo pump - 60 sqft FNS DE filter (with FiberClear), 1999 Sundance Optima 850 hot tub.
    Manassas Park, VA

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    In the Industry

    duraleigh's Avatar
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    Apr 2007
    Location
    Sebring, Florida
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    30,085

    Re: Pool draining

    Rahter than drain the entire pool, do so in increments of one foot or so if you are concerned about the water table.

    It DOES use more water but not as much as you might think if you do the math.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

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    Join Date
    Jul 2012
    Location
    SE Minnesota
    Posts
    137

    Re: Pool draining

    How much water has to be replaced to reach your target number? If you can leave some water in the pool it may be a non issue.

    Just thinking out loud...a person can buy a post hole digger for about $20. If you dug a 6" dia hole as deep as your pool is and never encountered water, or let it sit like that for a day and water never seeped into the hole, would that indicate the water table is lower than your pool?
    Intex Ultra Frame 26'x52"
    Intex 2,500 gal/hr pump with Unicel cartridge filter.

  5. Back To Top    #5

    Re: Pool draining

    I live in Houston where we don't have basements because of the water table. I had to drain a lot of water to lower my cya from 200 to about 65. I was concerned about the water table. I was able to drain 14" without having any issues. I did about 5 drains overall, most about 6-7", but the big one was 14".
    19,500gal, Gunite, Pebbletec, Chlorine, PCC2000 cleaner, Stenner Chlorine Pump, MegaCatch Mosquito Trap

  6. Back To Top    #6
    Richard320's Avatar
    Join Date
    Jan 2010
    Location
    San Dimas, CA (LA County)
    Posts
    18,768

    Re: Pool draining

    It takes some hunting around, but it looks like the closest well that is monitored has never been less than 17 feet to water. http://www.water.ca.gov/waterdatalibrar ... 19W14K004S

    Here's the main map console. http://www.water.ca.gov/waterdatalibrary/

    In short, unlikely to float the pool.
    16K freeform gunite with spa; Pentair 4000 DE filter; Century Whisperflow 1 HP; Pentair Minimax heater.
    Troublefree does not mean Maintenancefree. It's like brushing your teeth: You can spend a couple minutes a day and pennies a week or go to the dentist once a year and spend several thousand dollars.
    A pool is like a pet - you have to feed it every day, even the days you don't want to play with it!

  7. Back To Top    #7

    Join Date
    Aug 2012
    Location
    Near Sacramento, CA
    Posts
    47

    Re: Pool draining

    Hey everyone, thanks for all the help. Ya, my pool is only around 7'-6" or so deep so I think I'm probably safe. I'll probably empty a little and see what happens and then keep emptying it out. I'll let you know what I find!
    Outdoor IG Plaster Pool @18,000 gallons
    Cartridge Filter: Jandy CL580 (filter area 580 ft2, Max Flow 150 gpm, 6-hr capacity 54,000g)
    Pool Built est. 2002

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