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Thread: Stubborn algae bloom

  1. Back To Top    #1

    Join Date
    Jun 2009
    Location
    Central NJ
    Posts
    6

    Stubborn algae bloom

    OK, I admit it, I'm a noob. 36K gal pool with vinyl liner. And yes I've read a lot of the info here on dealing with algae, but only after I had already gone down the following frustrating path:

    1) opened pool 3 weeks ago. totally green and cloudy.
    2) shock with dichlor powder and adjust ph and alkalinity using test strips (yeah I know, a REAL test kit has been ordered and is on the way). Vac'd to waste what a could, a challenge when you can't see the bottom
    3) 3 weeks later, still green and cloudy; my CYA is probably off the charts -- as near as I can tell from the test strip, probably in the 100 range. FC is dark purple on the test strip, something over 10, but yeah prob. not enough to really treat the algae given the high CYA
    4) call my pool guy. He says to use (gasp) copper algaecide. I add enough per the instructions to initially treat 40K gallons. Makes a little bit of a difference, but not enough. Meantime, it plunges my FC to zero (according to the test strips)

    So after reading all the info here, once my test kit arrives I'm ready to go and buy out costco's supply of clorox unscented bleach and set off a chlorine bomb in the pool.

    My real question is, can I do so safely after having already added 16 oz. of copper algaecide to the pool? My pool guy seemed to indicate that too much FC will cause the the copper to stain the pool. But I'm going to need a LOT of bleach given my high CYA. Feel like I'm in a catch 22... what should be my next step? Any help/suggestions would be appreciated. There's a reason my username is what it is... wish I had found this site earlier
    36K gallon IG pool, vinyl liner
    Hayward sand filter
    Hayward heat pump heater

  2. Back To Top    #2

    Re: Stubborn algae bloom

    Don't worry, I had a heck of a time getting my pool cleared this summer!

    Everyone here knows so much, I'm sure they will comment on what steps you should take next. This is the second year that these guys have moved me from swamp thing to clean, clear water!
    26,000 gal liner IG pool
    Doughboy with concrete construction
    Full sun most of the day
    1.5 hp pump system
    200lb sand filter

  3. Back To Top    #3
    frustratedpoolmom's Avatar
    Join Date
    May 2007
    Location
    SWSuburban Chicago, IL
    Posts
    11,965

    Re: Stubborn algae bloom

    You need to do a partial drain and refill, and maybe repeat - to lower the CYA level. This will also get rid of some of the copper. You don't want copper in your pool!

    Shocking your pool with high CYA is a losing battle.

    Once you have your kit you'll be able to test accurately, but I'd go ahead and drain down a foot and refill.
    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
    http://www.PerfectlyClearPoolService.com

  4. Back To Top    #4

    Join Date
    Jun 2009
    Location
    Central NJ
    Posts
    6

    Re: Stubborn algae bloom

    Thanks for the quick reply. So I'm thinking...

    1) drain pool 1+ ft, then refill
    2) test water
    3) then shock with liquid chlorine per the pool school procedure for getting rid of algae

    Should I be looking for a target CYA before attempting the shock step... 60? 50? And in the meantime, with a current FC of nearly zero, is the algae going to take off again, or will the copper, bad as it is, keep the algae somewhat at bay? In other words, should I have maintenance level of chlorine in there while waiting for the test kit? And will chlorine cause the copper to stain the pool, as my pool guy hinted?

    Good thing I have empty garage space for all those empty bleach bottles I'm going to have this weekend...
    36K gallon IG pool, vinyl liner
    Hayward sand filter
    Hayward heat pump heater

  5. Back To Top    #5
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: Stubborn algae bloom

    Finish lowering your CYA level before shocking.

    A good CYA level to aim for is around 50. If you have a SWG you can leave CYA a little bit higher.
    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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