Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 13 of 13

Thread: I have high chlorine levels but algea keeps coming back

  1. Back To Top    #1

    Join Date
    Jul 2013
    Location
    Wyckoff, NJ
    Posts
    7

    I have high chlorine levels but algea keeps coming back

    A few weeks ago we came back from vacation to find a family of ducks in the pool. We got them safely relocated, but were left with algae on the walls. I've shocked, brushed, backwashed and vacuumed a few times, but it still keeps coming back.

    Currently I've got very high Free Chlorine of 17.25 ppm (due to three shocks in the last two weeks) but algea still grows. (Shouldn't that chlorine level prevent further growth?)

    My pool store keeps advising algaecide, but everything I hear saiys it's bad for the filter.

    Should I try to shock harder? Do I have to deal with the CYA? (I'd rather not drain the pool.) WILL algeacide help?

    I'm at a loss for what to try next. Any advice is appreciated.

    Here are test results (from pool store - Anthony & Sylvan, which uses electronic testing):

    FC: 17.25 ppm
    CC: 0 ppm
    pH: 7.6
    TA: 74 ppm (have been advised to raise it
    CH: 200 ppm
    CYA: 100 ppm
    30K gal, IG plaster, Hayward DE4820 48 sqft DE filter, 1 HP A.O. Smth pump, heater (usually off), Polaris 360 pool cleaner, built 1992

  2. Back To Top    #2

    Join Date
    Jun 2013
    Location
    SpringHill FL
    Posts
    415

    Re: I have high chlorine levels but algea keeps coming back

    If you want an easy to maintain crystal clear pool you need to invest in a quality fas/dpd test kit. Poolstores are in buisness to make money not test your water accurately for free.
    Nathan
    15x30 gunite 18k gallons Hayward star clear plus 120sqft cart

  3. Back To Top    #3
    pwrstrk's Avatar
    Join Date
    Aug 2012
    Location
    Elverson Pa.
    Posts
    4,758

    Re: I have high chlorine levels but algea keeps coming back

    Read the SLAM process in pool school. SLAM stands for shock level and maintain. You also need a good test kit to SLAM.

    The reason it keeps coming back is your not following thru with the SLAM.


    Jeff
    24'x54" AG Morada RTR (by wilbar) 13'500 gal. Hayward Powerflo Matrix 1hp 2 speed. Hayward Perflex EC65 DE filter.

  4. Back To Top    #4

    Join Date
    Jul 2013
    Location
    Wyckoff, NJ
    Posts
    7

    Re: I have high chlorine levels but algea keeps coming back

    Thanks, I just ordered a TF-100 test kit. In the meantime, I read the SLAM instructions, and it seems to say that I need to get the FC higher than the current 17 ppm. But if I add shock won't that raise the CYA?
    30K gal, IG plaster, Hayward DE4820 48 sqft DE filter, 1 HP A.O. Smth pump, heater (usually off), Polaris 360 pool cleaner, built 1992

  5. Back To Top    #5
    pwrstrk's Avatar
    Join Date
    Aug 2012
    Location
    Elverson Pa.
    Posts
    4,758

    Re: I have high chlorine levels but algea keeps coming back

    We like to use liquid chlorine for the SLAM. Bleach is the way to go.

    Good job on getting the test kit. It's a must have. You need that so you know where your levels are for the SLAM.


    Jeff
    24'x54" AG Morada RTR (by wilbar) 13'500 gal. Hayward Powerflo Matrix 1hp 2 speed. Hayward Perflex EC65 DE filter.

  6. Back To Top    #6

    Join Date
    Jun 2013
    Location
    SpringHill FL
    Posts
    415

    Re: I have high chlorine levels but algea keeps coming back

    Unless your cya is low or you plan to drain and refill the tabs are not a good idea. Most of us use simple unscented laundry bleach
    Nathan
    15x30 gunite 18k gallons Hayward star clear plus 120sqft cart

  7. Back To Top    #7
    pwrstrk's Avatar
    Join Date
    Aug 2012
    Location
    Elverson Pa.
    Posts
    4,758

    Re: I have high chlorine levels but algea keeps coming back

    The problem with the test results you have is we can't trust them. Espically the cya test.


    Jeff
    24'x54" AG Morada RTR (by wilbar) 13'500 gal. Hayward Powerflo Matrix 1hp 2 speed. Hayward Perflex EC65 DE filter.

  8. Back To Top    #8
    Mod Squad woodyp's Avatar
    Join Date
    Apr 2010
    Location
    East Texas
    Posts
    8,999

    Re: I have high chlorine levels but algea keeps coming back

    It is highly likely that your CYA level is well over 100. It makes fixing problems with algae all that much harder due to FC requirements at those levels. Algaecide will NOT help. You'll be better off draining it by at least a third before your kit comes in.
    16x32x52" Steel Cornelius Miramar AGP Vinyl liner 13,100 gal. Buried 2 ft.
    2 Speed Hayward Power-Flo Matrix 85 g.p.m. 22" 250lb. sand filter hard plumbed
    Pool Rover Jr., Pool Blaster Max, Diver Dave TF100 Test Kit/Speed Stir
    Margaritaville Frozen Concoction Maker, Liqour Chiller, & Drink Mixer & Party Tub----Collect 'um all!

  9. Back To Top    #9

    Join Date
    Jul 2013
    Location
    Wyckoff, NJ
    Posts
    7

    Re: I have high chlorine levels but algea keeps coming back

    Ugh. I will likely have to drain by 1/3 or so to reduce the CYA. It was 90 ppm last week, prior to a shock treat with Di-Scholor Super Pool Treat. But now I understand that the shock treatment added CYA.

    On the liquid bleach, can I just use Clorox? And if so, how do I know how much to use?

    Thanks.
    30K gal, IG plaster, Hayward DE4820 48 sqft DE filter, 1 HP A.O. Smth pump, heater (usually off), Polaris 360 pool cleaner, built 1992

  10. Back To Top    #10

    Join Date
    Sep 2011
    Location
    Miami Beach, FL
    Posts
    125

    Re: I have high chlorine levels but algea keeps coming back

    32000 gallon, inground, fiberglass, Aqua-Rite SWG, Pentair 420 sqft cartridge filter (Installed-ya baby), Hayward Super II pump 1.5 hp, 144k BTU heat pump, Dolphin Dx5 Plus, and a good test kit from Duraleigh!

  11. Back To Top    #11
    pwrstrk's Avatar
    Join Date
    Aug 2012
    Location
    Elverson Pa.
    Posts
    4,758

    Re: I have high chlorine levels but algea keeps coming back

    Get the bleach at Walmart. Their brand. It's cheaper there. Just plain non scented bleach.


    Jeff
    24'x54" AG Morada RTR (by wilbar) 13'500 gal. Hayward Powerflo Matrix 1hp 2 speed. Hayward Perflex EC65 DE filter.

  12. Back To Top    #12

    Join Date
    Jun 2012
    Location
    Howell, NJ
    Posts
    977

    Re: I have high chlorine levels but algea keeps coming back

    The problem is that your CYA may be higher than 100, which would mean you need to drain more than 1/3. If your CYA is 150, you will need to drain 2/3. You would probably be safe to drain 1/3 now, but wait until you get your kit to go any further.
    John
    7 year old ~13,500 gal 24' AGP with 1.5 hp Proline pump, 150 sqft Pleatco cartridge, filled with well water with pH of about 4.5.
    Wanda the Whale pool vacuum, home made heater, Taylor K-2006
    Cloudy Pool? 1) Order test kit. 2) Follow SLAM
    New to TFPC? Read Pool School a few times, then post questions. PoolMath will help with chemical additions.

  13. Back To Top    #13

    Join Date
    Jul 2013
    Location
    Wyckoff, NJ
    Posts
    7

    Re: I have high chlorine levels but algea keeps coming back

    Thanks everyone.
    30K gal, IG plaster, Hayward DE4820 48 sqft DE filter, 1 HP A.O. Smth pump, heater (usually off), Polaris 360 pool cleaner, built 1992

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •