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Thread: Algae keeps coming back

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    Question Algae keeps coming back

    Upon opening the pool this season, we SLAMmed successfully. After a few weeks an algae bloom generated from our wedding cake stairs. We removed those and successfully SLAMmed again. For several weeks the pool water was clear, then a little cloudy. Now, seeing algae on the bottom of the pool again.

    We have a Hayward cartridge filter. I have 2 cartridges and I swap out the dirty for clean when the pressure increase past 20 and at the first sign of cloudiness. FC has been maintained between 3-5.

    I think the recurrence of algae is coming from the cartridges never truly being free from algae. How can I treat/clean the cartridges to make sure I an not reintroducing a problem each time I switch one out?

    Current numbers:

    FC = 3.0
    CC = 1.0
    pH = jumped today about 8.2

    Ready to SLAM and add muriatic acid.

    Is a different filter system the answer?

    Not using the Nature2Vision Pro sanitizer currently.
    TerriP
    27'x54" AGP - 2HP Hayward SWIMPRO LX PUMP - SW150 Hayward SWIMPRO Voyager Element Tank- - Dyna-Skim Wide Mouth Skimmer SP1091WM - Aquaray vaccuum

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    harleysilo's Avatar
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    Re: Algae keeps coming back

    What's your CYA level?
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    Re: Algae keeps coming back

    If you are slamming correctly and keeping your FC/CYA ratio correct then the cartridges wouldn't be too much of an issue.

    What's your cya level?
    16K Gal Plaster | Compupool SWG | Intelliflow VF | TF-100

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    Re: Algae keeps coming back

    The last two summers, I struggled with recurring algae on the walls and steps. I was even maintaining the highest FC level for my given CYA level. I would brush it constantly, perform SLAM's, pull out the light, etc. etc. This summer, I have not had one hint of algae in the pool. It has made me lazy about brushing the walls to be honest.

    The only thing I did was get a new cartridge from Amazon. I tried a Pleatco Advanced brand this time around. The filter media feels a bit different than an old Pleatco and Unicel that I had. And the Pleatco Advanced is so much easier to clean with a hose. I would advise that you SLAM first if you do decide to change your filter.

    I'm not saying it's the magic fix, but if you might need a new cartridge anyway, it was worth the 40 dollars for me.
    10,000 gallon in ground diamond brite, Circupool si30+, Hayward C900 cartridge, 1.5hp Flotec single speed pump

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    Re: Algae keeps coming back

    How long are you running the pump? Do you have good circulation around the steps? Mine are on the opposite side from the return, so I periodically pour a little bleach behind them (not wedding cake type, so there is a gap between the pool wall and the steps) and swish it around under and behind the steps. If your CYA is above 40, then you are not staying above the minimum FC and algae can occurr.
    26' X 52" Intex Ultra Frame. Intex Sand Filter
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    You can lead a horse to (clear) water, but you can't force him to swim in it!

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    Re: Algae keeps coming back

    Filtration has virtually nothing to do with the presence of live algae. Chlorine kills it. A new cartridge will not.

    Post your CYA number but algae forms when the chlorine is too low and is killed when the chlorine is adequate for your CYA.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
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    Re: Algae keeps coming back

    Quote Originally Posted by duraleigh View Post
    Filtration has virtually nothing to do with the presence of live algae. Chlorine kills it. A new cartridge will not.

    Post your CYA number but algae forms when the chlorine is too low and is killed when the chlorine is adequate for your CYA.
    Agreed.

    If you completed a SLAM by meeting all 3 criteria, all algae in the water should be dead, filter included. You are most likely letting your FC get too low.
    Dom - TFP Guide
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    Re: Algae keeps coming back

    Checked the CYA last week and it was at 45. Now I am out of that solution in the TF100 kit. Waiting for new one to arrive.

    I took the stairs out weeks ago.


    TerriP
    27'x54" AGP - 2HP Hayward SWIMPRO LX PUMP - SW150 Hayward SWIMPRO Voyager Element Tank- - Dyna-Skim Wide Mouth Skimmer SP1091WM - Aquaray vaccuum

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    Re: Algae keeps coming back

    Quote Originally Posted by TerriP View Post
    Checked the CYA last week and it was at 45. Now I am out of that solution in the TF100 kit. Waiting for new one to arrive.

    I took the stairs out weeks ago.


    Sent from my iPhone using Tapatalk
    Round up the CYA to 50ppm, and your minimum FC is 4ppm. Letting your pool go close to and below 4ppm (your OP shows FC 3.0ppm) is allowing algae to reproduce fast enough to overtake the low level of chlorine. The FC target for your CYA is 6ppm.

    I recommend that you try a FC of 6ppm as your minimum, with a target FC of 8ppm.

    Are you currently SLAMming at a FC of 20ppm?
    Dom - TFP Guide
    Intex 18' X 48" Ultra Frame AGP 6700 gallons | Two Intex CS8110 SWG's | Hayward Pro Series 21" Sandfilter | Hayward 1.5HP Power Flo Matrix pump | Hayward Thru-wall Skimmer | Wanda the Whale | 72 sq ft of Sungrabber Solar Panels with Hayward GLC-2P-A | Taylor K2006 Test Kit, Sample Sizer & Speed Stir | Click Here To Become a TFP Supporter!

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    Re: Algae keeps coming back

    I was slamming to 16. For the future I'll keep FC about 6


    TerriP
    27'x54" AGP - 2HP Hayward SWIMPRO LX PUMP - SW150 Hayward SWIMPRO Voyager Element Tank- - Dyna-Skim Wide Mouth Skimmer SP1091WM - Aquaray vaccuum

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