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Thread: Fighting algae for over 6 weeks

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    Fighting algae for over 6 weeks


    This is my first post to this board. I felt I had no option as I have been fighting my pool the entire summer season and am definitely ready to give up. Here is my story.

    I cant remember exactly when this started, or what may have triggered it, because now it feels as if I have been fighting this problem the entire season. Everyday after I have vacuumed to waste, the next day I find more algae in small circular sections of the pool floor. The color is a dark brown that disperses quickly into the pool like a powder on touch. Ive taken my pool water sample into pool stores around the city and they tell me my water is fully balanced. The pool is crystal clear and not cloudy, but everyday has algae on the pool floor. Here is what I have tried:

    NOTE: I have an above ground pool, 18X33 in size.
    - shocked on a weekly and sometimes bi-weekly basis with anywhere between 700-1000g of super shock.
    - vacuumed to both filter and waste at the beginning but over the past 3 weeks, have only been vacuuming to waste on almost a daily basis
    - was directed by a pool professional at the pool store to chance my filter sand. Did that with no change.
    - used filter cleaner solution 4 times, 3 times with the old sand, once with the new sand
    - thinking my filter was on the fritz, i placed the filter on recirculate for the past week. The amount of algae I found everyday was a less, but far from eliminated. So now I am not even using the filter and I still see algae coming back
    - Did notice several weeks ago after I had vacuumed, turned off the filter, removed the vacuum, and turned the filter back onto filter, a large amount of browny substance suddenly came out of the outlet and into the pool.

    Any ideas? I am considering shutting down the pool this year and next year draining the pool completely and starting with fresh new water for the entire pool.
    27,000 gal freeform, 3ft.-7.5 ft., 675 sq.ft., 50 sq. ft. 18" raised spa w/ 2 hp blower, 60% Color quartz plaster, Hayward 450 sq. ft. cartridge filter, Hayward 2hp 2 speed pump, 400,000 BTU propane heater, SWG, Goldline PS 8, Hayward Phantom cleaner

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    In the Industry
    duraleigh's Avatar
    Join Date
    Apr 2007
    Sebring, Florida

    Re: Fighting algae for over 6 weeks

    Welcome to the forum. Your pool can be easily cleared up if you follow the guidelines folks on this forum will give you.

    1. The filter is not your problem.

    2. Algae is your problem

    3. Chlorine kills just haven't been using enough of it.

    4. You need to properly shock your pool. Shock is a process than can take several days to completely rid your pool of the algae.

    5. In order to shock properly, you need to purchase a high quality test kit and start performing your own, accurate testing and stay out of the pool store.

    6. In order to get this ball rolling, you need to post test results from your pool. pH, TA, FC, CYA, and CH
    Dave S. - Forum owner
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

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    dattia's Avatar
    Join Date
    Jun 2008
    West Chester, PA

    Re: Fighting algae for over 6 weeks

    Are you sure it is algae and not just dirt or pollen. I have crystal clear balanced water and I have "stuff" on the bottom of my pool every day, as do many here.
    27' round AG
    Hayward Matrix 1 1/2 HP Pump
    Hayward S210T Sand Filter

  4. Back To Top    #4

    Join Date
    Jan 2009
    Cupertino, CA

    Re: Fighting algae for over 6 weeks

    Given a good test kit, you'd be able to do an Overnight FC Test to see if there is a low-level algae situation. If there is, the answer is to raise FC to shock level (see the Chlorine/CYA chart) long enough to kill it all off for good. If there isn't, then the accumulation is likely dirt/pollen; with a sand filter, one option would be to add a small amount of DE (1/2 lb) to "dirty" it a little which will make the sand more effective.
    BBB "Intermediate Swimmer"
    IG plaster pool 18.5K gal, Hayward Pro-Grid DE filter, 3/4 HP Hydramax II; Polaris 380, 3/4 HP booster
    AG spa 325 gal, probably Sundance of some kind
    Water testing instructions on one page

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    frustratedpoolmom's Avatar
    Join Date
    May 2007
    SWSuburban Chicago, IL

    Re: Fighting algae for over 6 weeks

    Quote Originally Posted by aplus
    Did notice several weeks ago after I had vacuumed, turned off the filter, removed the vacuum, and turned the filter back onto filter, a large amount of browny substance suddenly came out of the outlet and into the pool.
    Whether it's algae or not (which an overnight test can help confirm) the above shouldn't happen. Something isn't right - and are you "rinsing" after backwash? You shouldn't see anything coming from the return - this does suggest something inside the filter is at the very least part of the problem.
    Helpful links: Pool School; CYA/Chlorine Chart
    24' round AG pool, 52" high, Raypak heater; Waterway 2 spd Pump;
    150 Sq ft. Clearwater Cartridge Filter; Former and DISSATISFIED "Pool Frog" owner

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