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Thread: Draining recommendations

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    Join Date
    Apr 2013
    Location
    Ellicott City, MD
    Posts
    10

    Draining recommendations

    Hi all:

    So I ran a first set of partial tests last night and got the results below:

    FC - .2
    CC - 2.2
    pH - 7
    TA - 110
    CH - didn't test - toddler bed-time intervened
    CYA - off the charts - tested 3X
    Borates - not using

    I shocked the **** out of the pool last night using the last of the HTH-3 shock left by the previous owner.

    I know I need to drain the pool; however, I'm wondering if there are any tips. I saw places that I should plug my skimmers since it's a Sylvan pool and I only have one hole in my skimmer for the vacuum hose.

    As an FYI, I want to use the BBB method, but had Tri-Chlor tablets left over from the previous owner, so I was attempting to use them up. Everything looked good until I got the K-2006 and played with it last night. I was told by the pool store that my Alkalinity was low and to add Algaecide and did that over the weekend, but hoo-boy, I didn't expect this. I assume I'm going to need to do a lot of draining to get down into a reasonable CYA level (I was only 1/2 way to 100 before I could no longer see the dot).

    Anyway, any advice would be really appreciated. I'm probably going to try to tackle it tomorrow after I can get my hands on a new 50 foot hose (I don't want to erode the hill on the filter side of my pool).

    Thanks,
    Shawn
    30,000 gallons, IG, plaster, Hayward S-240 Sand Filter, 1.5 HP Hayward Super Pump (unsure of speed)
    Built circa 1980.

  2. Back To Top    #2
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: Draining recommendations

    Welcome to TFP!

    To get a better ideal of what your CYA level might actually be you can do the test again with dilution. Mix equal amounts of pool water and tap water together, do the CYA test again using that as you pool water sample, then multiply the result by two. Doing the test this way has less precision, but it will tell you if CYA is somewhere near 100 or way over 200.

    Before draining too far, make sure your local water table is below the level you want to drain to. If you have any doubts about the water table depth you might want to do a number of partial drains. If the water table is too high and you drain the pool it can sometimes pop right out of the ground.
    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

  3. Back To Top    #3

    Join Date
    Apr 2013
    Location
    Ellicott City, MD
    Posts
    10

    Re: Draining recommendations

    Thanks!! Glad to have found this site. It's helped with a lot of my novice pool confusion. I checked tonight (using the method above) and it looks like my CYA is 180-200. So, quite a bit of draining in my future. I have the FC up to 18 now, so I'm hopeful it will limit algae potential. I was going to straight to the storm drain with my pool drainage. I don't think my drainage goes directly to the Chesapeake (I'm in Ellicott City, MD). I didn't check anything else because I didn't think it was necessary until I got the CYA under control. Thanks again all!
    30,000 gallons, IG, plaster, Hayward S-240 Sand Filter, 1.5 HP Hayward Super Pump (unsure of speed)
    Built circa 1980.

  4. Back To Top    #4

    Join Date
    Apr 2013
    Location
    Ellicott City, MD
    Posts
    10

    Re: Draining recommendations

    So I drained it over the weekend and got the CYA down to between 70-75. They're calling for rain for the next week or so here in MD, so I'm hoping that will further bring it down without me needing to do additional drains (dilution, then evaporation when the sun makes an appearance maybe?). Is that ok or should I drain it a little more to bring it down to a more manageable level? I know with a CYA this high, I'll need to keep a higher level of FC and make a few other tweaks to get me into optimal range. Any other issues anyone can see?

    My most recent (today) test results are below:

    FC - 3.8
    CC - .4
    ph - 7.2
    TA - 90
    CH - 180
    CYA - 70-75

    Thanks and happy (almost) swim season!

    -Shawn
    30,000 gallons, IG, plaster, Hayward S-240 Sand Filter, 1.5 HP Hayward Super Pump (unsure of speed)
    Built circa 1980.

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    msgtdan's Avatar
    Join Date
    Jul 2011
    Location
    SW MO
    Posts
    653

    Re: Draining recommendations

    CYA won't evaporate out, but backwashing and pumping to waste to lower after a rain will. If you're testing Chlorine using 25ml to get the .2 precision, it's not necessary, use 10ml for .5 precision and save on your chems.
    Dan D
    Used 2003 Aqua Leader 27'x52", 17,800 w/10" hopper, SwimPro SW256T 250# sand filter, Hayward PowerFlo LX pump 1hp impellor, Emerson 1 1/2 hp motor, setup Aug 2012 Summer 2011 used Summer Escapes Ring pool 14' x 42", Intex 1600gph sand filter, HTH 6 way test kitTF-100 w/stirrer, Well water @ FC=0, PH=7.2, TA=290, CH=320

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    thehowheels's Avatar
    Join Date
    Apr 2013
    Location
    SoCal
    Posts
    120

    Re: Draining recommendations

    Quote Originally Posted by smcclurg
    So I drained it over the weekend and got the CYA down to between 70-75. They're calling for rain for the next week or so here in MD, so I'm hoping that will further bring it down without me needing to do additional drains (dilution, then evaporation when the sun makes an appearance maybe?). Is that ok or should I drain it a little more to bring it down to a more manageable level?
    As water evaporates, the CYA will stay in your pool. The only way the rain could remove CYA is if it rains so much your pool overflows and goes down the drain.
    Matt
    9k gallon, plaster, IG. Raised spa w/ spillover into pool. AO Smith Century Centurion / Purex Triton WisperFlo 0.5 HP, Hayward 1.5 HP (spa), Polaris 1-516-01 1.5 HP (blower). Hayward DE3620 36 ft2 72 GPM DE Filter, Polaris 145 cleaner. Pool built ~1980.
    Trouble-free, BBB since: April 25, 2013

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