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Thread: Small amout of recurring green algae

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    Small amout of recurring green algae

    I seem to constantly have a small amount of green algae. It is mostly found on the steps and in tight corners. (where the sweep doesn't go)

    Today's test results:
    FC=1.8 (I added16 oz. 12.5%chlorine)
    CC=0
    PH=7.9 (I added 22 oz. muriatic acid)
    TA=110
    CH=400
    CYA=45
    Temp=85 (we like it warm)
    SI=0.5

    I run the filter for 5 hours a day, with Jandy Aquapure set at 90%.
    I currently do not use, or test for borates.

    I am pretty confident that if I were to go to Leslie's, they would tell me that my phosphates are high, and recommend adding Phosfree. (from past years experience)
    I am trying to stay within the TFP way of thinking.

    Is there something obvious that I am missing?

    Thanks in advance.

    Mike
    12,000 Gal plaster pool & spa.
    Jandy 2.7HP V.S. e pump, with IQpump control.
    Jandy AquaPure 1400. Jandy PDA.
    Solar heat. Jandy 400btu ng heater.
    Pentair 420 cartridge filter. Polaris 360 sweep.

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    Mod Squad tim5055's Avatar
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    Re: Small amout of recurring green algae

    Your testing this morning shows why it I s happening. You are letting your FC drop too low at times and the steps are probably an area of poor circulation, thus they probably run a little lower. You have a low level algae colony living in the water and the SWCG can't really keep up.


    Turn off the SWCG and SLAM with liquid chlorine. Once the algae is gone you should bring the CYA up to 70 or so and start the SWCG again.
    Last edited by tim5055; 08-01-2015 at 04:23 PM. Reason: I'm not crazy, the auto type on my iPad doesn't understand what I'm trying to say.....
    TFP Moderator 39 X 18 23,000(ish) freeform gunite; built 2007ish; Pentair Triton II TR100 600lb Sand filter; 2 HP Pentair pump with 2.2 HP AO Smith single speed motor; 2 skimmers, 1 main drain, 4 returns w/waterfall, Stenner 45MHP2 3GPD running@ 60% - 15 gal Tank; heated by the sun CYA 200+ when I started - 50 now. Dolphin Supreme M5 Pool Cleaner. Hot Springs SX Spa, 285 gallon

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    Re: Small amout of recurring green algae

    I would put enough stabilizer now to bring the cya to 70. Then slam based on 70. It could take up to a week for the new cya level to test properly
    12 x 26 Viking FG IG, Bermuda Model, 3 1/2' to 5', 7000 Gallons, Diamond Series Maya, Hayward 1 1/2 HP Maxflo VS, Hayward Stay Clear Plus Cart Filter C17502(S), Hayward Aqua Rite SWG w/T3 cell, Color Changing FIBERSTAR Lighting, Aqua Bot Supreme Robotic cleaner, Brushed Concrete with CCI Liberty Tan color, Taylor K-2006 test kit, Armor Foundation penetrating concrete sealer(lifetime warranty).

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    Re: Small amout of recurring green algae

    Quote Originally Posted by rmturner54 View Post
    I would put enough stabilizer now to bring the cya to 70. Then slam based on 70. It could take up to a week for the new cya level to test properly
    I wouldn't. I'd slam at 45 and leave CYA right where it is. During the SLAM process, the pool is a bleach pool. The difference is maintaining shock level of 18 versus 28!!!

    When the algae has been defeated for once and for all, then see about raising CYA to ease the burden on the SWG.
    16K freeform gunite with spa; Pentair 4000 DE filter; Century Whisperflow 1 HP; Pentair Minimax heater.
    Troublefree does not mean Maintenancefree. It's like brushing your teeth: You can spend a couple minutes a day and pennies a week or go to the dentist once a year and spend several thousand dollars.
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    Mod Squad tim5055's Avatar
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    Re: Small amout of recurring green algae

    I agree with Richard, raising the CYA now is just going to add cost to the SLAM in additional chlorine. Wait until after the SLAM is complete to adjust it.
    TFP Moderator 39 X 18 23,000(ish) freeform gunite; built 2007ish; Pentair Triton II TR100 600lb Sand filter; 2 HP Pentair pump with 2.2 HP AO Smith single speed motor; 2 skimmers, 1 main drain, 4 returns w/waterfall, Stenner 45MHP2 3GPD running@ 60% - 15 gal Tank; heated by the sun CYA 200+ when I started - 50 now. Dolphin Supreme M5 Pool Cleaner. Hot Springs SX Spa, 285 gallon

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    Re: Small amout of recurring green algae

    I only suggested that based on what i have read. I have read it both ways.
    12 x 26 Viking FG IG, Bermuda Model, 3 1/2' to 5', 7000 Gallons, Diamond Series Maya, Hayward 1 1/2 HP Maxflo VS, Hayward Stay Clear Plus Cart Filter C17502(S), Hayward Aqua Rite SWG w/T3 cell, Color Changing FIBERSTAR Lighting, Aqua Bot Supreme Robotic cleaner, Brushed Concrete with CCI Liberty Tan color, Taylor K-2006 test kit, Armor Foundation penetrating concrete sealer(lifetime warranty).

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    Re: Small amout of recurring green algae

    I do see how it would add a higher cost though. Thanks.
    12 x 26 Viking FG IG, Bermuda Model, 3 1/2' to 5', 7000 Gallons, Diamond Series Maya, Hayward 1 1/2 HP Maxflo VS, Hayward Stay Clear Plus Cart Filter C17502(S), Hayward Aqua Rite SWG w/T3 cell, Color Changing FIBERSTAR Lighting, Aqua Bot Supreme Robotic cleaner, Brushed Concrete with CCI Liberty Tan color, Taylor K-2006 test kit, Armor Foundation penetrating concrete sealer(lifetime warranty).

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    Re: Small amout of recurring green algae

    OK.
    Thanks for the responses.
    I will read-up on the SLAM method.
    I will report back with my amazing success!!!

    ;o)
    12,000 Gal plaster pool & spa.
    Jandy 2.7HP V.S. e pump, with IQpump control.
    Jandy AquaPure 1400. Jandy PDA.
    Solar heat. Jandy 400btu ng heater.
    Pentair 420 cartridge filter. Polaris 360 sweep.

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    Mod Squad tim5055's Avatar
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    Re: Small amout of recurring green algae

    Quote Originally Posted by newmaac View Post
    OK.
    Thanks for the responses.
    I will read-up on the SLAM method.
    I will report back with my amazing success!!!

    ;o)
    Read through it and ask questions. It is totally against what pool stores teach, so we understand it may not feel right. Ask questions. We want you to succeed quickly.

    Did I say don't be afraid to ask questions?
    TFP Moderator 39 X 18 23,000(ish) freeform gunite; built 2007ish; Pentair Triton II TR100 600lb Sand filter; 2 HP Pentair pump with 2.2 HP AO Smith single speed motor; 2 skimmers, 1 main drain, 4 returns w/waterfall, Stenner 45MHP2 3GPD running@ 60% - 15 gal Tank; heated by the sun CYA 200+ when I started - 50 now. Dolphin Supreme M5 Pool Cleaner. Hot Springs SX Spa, 285 gallon

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    Re: Small amout of recurring green algae

    Thanks, Tim.
    You are right, this defies what I have been taught.
    We have always tried to minimize the amounts of chemicals added to the water, hence the SWG to begin with.

    So SLAM....Shock, level and maintain.
    I have read a few articles and I think that I get the shock and maintain part.
    I will go back and read again, but I am not understanding the "level" part.
    Once I raise the FC to 17ish, and successfully kill-off any remaining algae, do I just wait for the FC level to naturally come back down to a normal level, THEN start maintaining with the SWG?
    I am using the 17 FC value loosely. Reading the chlorine/CYA chart,
    Pool School - Chlorine / CYA Chart
    it doesn't show a selection of having a SWG AND a CYA of only 45.

    I like the Overnight test idea. I will be doing that, to get a better idea of the situation. There is very little visible algae, it just never goes away!
    With the water temp being high, and the awesome sunny days recently, the SWG just doesn't seem to be able to keep up.

    Mike
    12,000 Gal plaster pool & spa.
    Jandy 2.7HP V.S. e pump, with IQpump control.
    Jandy AquaPure 1400. Jandy PDA.
    Solar heat. Jandy 400btu ng heater.
    Pentair 420 cartridge filter. Polaris 360 sweep.

  11. Back To Top    #11

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    Re: Small amout of recurring green algae

    It's more like; "ShockLevel And Maintain". You need to get up to Shocklevel and then Maintain it there until you pass all 3 criteria. Then you let it drift down to the proper FC for your CYA. In your case, since you have a SWCG, after you are successful with the SLAM, you will want to raise the CYA to 70 and turn your SWCG back on.

    Before all that though, you need to check on your pH again. It's recommended that it be 7.2 before you start the SLAM. Once your FC is above 10 the pH test will not read correctly. So it's best to adjust it before that happens. Once the SLAM is complete and the FC is below 10 you can retest and adjust if needed.
    Bob - Palm Beach by San Juan Pools. approx 5000 gals., Pentair 320 cartridge filter (all new guts installed by me), Goldline SWG, 'New to me' Kreepy Krauly Sand Shark, Intermec 104 Timer Test kit: TF-100 w/Speed Stir

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    Re: Small amout of recurring green algae

    And try to find a way to get some circulation over to the step area. I have read about special eyeballs that increase the effective circulation. Maybe one of them would help in your long term goal.
    Bob - Palm Beach by San Juan Pools. approx 5000 gals., Pentair 320 cartridge filter (all new guts installed by me), Goldline SWG, 'New to me' Kreepy Krauly Sand Shark, Intermec 104 Timer Test kit: TF-100 w/Speed Stir

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