Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 12 of 12

Thread: Thought it was poop.... black algae??

  1. Back To Top    #1
    Modawg2k's Avatar
    Join Date
    May 2013
    Location
    Phoenix, AZ
    Posts
    270

    Thought it was poop.... black algae??

    I've had black specs in my pebble that have been increasing over the past few weeks/months. I have a 3 year history of not maintaining my water chemistry very well up until a couple months ago when I found this site. With the exception of CH (which I plan on doing a drain in the next week), I've kept a good eye on my numbers lately. In the past week, my chlorine got knocked down to zero because my SWG breaker got tripped and I didn't test for a few days. I'm currently shocking it. Earlier this week, I went into the pool and took a pool wire brush to some of the black spots (which have a smooth, slimy feel to them) and they will scape off and disintegrate with some hard rubbing. Do you guys feel that black algae is the culprit here?

    My current reading:
    TC: 15.5 (more chlorine was added after reading to obtain shock level per pool calculator)
    pH: 7.8 (MA added to obtain 7.4 per pool calculator)
    TA: 80
    CYA: 80
    CH: 850


    ~15k gallons, 3'-5'-4' Figure 8 Shape In Ground
    Wetedge Satin Matrix Interior (Pebble)
    Paramount In-floor System
    Pentair IntelliFlo VS 3050, Pentair Triton II TR100 Sand Filter
    Pentair Intellichlor IC40 SWG

  2. Back To Top    #2
    linen's Avatar
    Join Date
    Jul 2010
    Location
    Twin Cities, MN
    Posts
    8,649

    Re: Thought it was poop.... black algae??

    It sounds like black algae...are they green on the inside?
    TFP Expert who uses Pool School and my TF100 test kit along with PoolMath for my: Round 11K gallon AGP with deep end, 20" sand filter, Matrix 1hp 2spd, 6 2ftX20ft solar panels (and solar cover!), Intex SWCG (copper bars disconnected) and a Rubadub hot tub (chlorine). The SLAM process is not finished until: 1. CC < 0.5 ppm, 2. An OCLT < 1.0 ppm and, 3. The water is crystal clear.

  3. Back To Top    #3
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: Thought it was poop.... black algae??

    Given that they don't come off with casual brushing, then if you can scrape off a bit of one of the black dots and smudge it across a piece of white paper, and it smudges green, then it is black algae.
    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

  4. Back To Top    #4
    Modawg2k's Avatar
    Join Date
    May 2013
    Location
    Phoenix, AZ
    Posts
    270

    Re: Thought it was poop.... black algae??

    I will check into that once my FC gets down from shocking , thanks guys
    ~15k gallons, 3'-5'-4' Figure 8 Shape In Ground
    Wetedge Satin Matrix Interior (Pebble)
    Paramount In-floor System
    Pentair IntelliFlo VS 3050, Pentair Triton II TR100 Sand Filter
    Pentair Intellichlor IC40 SWG

  5. Back To Top    #5
    techguy's Avatar
    Join Date
    Jul 2010
    Location
    Antelope, CA
    Posts
    2,687

    Re: Thought it was poop.... black algae??

    I would check before your shock is done and possibly even raise your FC since its already up. If the top scrapes offs and makes green smudges, scrub the tops off to let your nice high FC get into the base layer.

    You are safe to swim all the way up to the shock level in the PoolSchool chart which is much more aggressive than PoolCalculator.com. Above that you risk fading your suit but that may be a fair cost to rid your pool of the algae.
    -- Guy --
    10K gallons in 21' Round 52 inch wall Aqualeader AG, Hayward Power Flow LX 1.5 HP pump motor, Hayward Perflex EC50AC DE filter w/Cellulose, Wide mouth skimmer, 2013 new Diver Dan (craigslist) to replace the faded old Hayward AquaBug. TF-100

  6. Back To Top    #6
    Modawg2k's Avatar
    Join Date
    May 2013
    Location
    Phoenix, AZ
    Posts
    270

    Re: Thought it was poop.... black algae??

    Thanks. Any issues with being in the water to brush algae? Seems harder to get a good scrub with a pole
    ~15k gallons, 3'-5'-4' Figure 8 Shape In Ground
    Wetedge Satin Matrix Interior (Pebble)
    Paramount In-floor System
    Pentair IntelliFlo VS 3050, Pentair Triton II TR100 Sand Filter
    Pentair Intellichlor IC40 SWG

  7. Back To Top    #7

    Join Date
    Aug 2010
    Location
    Dallas, TX
    Posts
    4,052

    Re: Thought it was poop.... black algae??

    Are you using a regular brush or a wire brush on the pole? It takes some elbow grease for sure!
    Built in 1957 44,000 gallon in-ground, Wet Edge Primera Stone in Sky Blue, Intelliflo VF Pump, 600 lb. Pentair Triton II TR-100 Sand Filter, CircuPool RG 60 Plus SWG, TF-100 test kit
    If TFP has helped you, please click to SUPPORT TFP!

  8. Back To Top    #8
    Melt In The Sun's Avatar
    Join Date
    Oct 2009
    Location
    Tucson, AZ
    Posts
    3,899

    Re: Thought it was poop.... black algae??

    I'd get a little tiny wire brush (toothbrush size, like for cleaning paintbrushes) and scrape it underwater with goggles. In my experience, the big brushes don't work as well since you can't push as hard on a little spot.
    11,200 gal, Pebble-Tec; Tristar 2-speed 1hp - Swimclear 325 ft2 cart - SWG - A & A in-floor cleaner - Heat pump. For the poolside cooking, a Yoder Wichita and a Big Steel Keg!
    TF Test Kits -- PoolMath -- Pool School
    Make each day your masterpiece. - John Wooden

  9. Back To Top    #9

    Join Date
    Aug 2010
    Location
    Dallas, TX
    Posts
    4,052

    Re: Thought it was poop.... black algae??

    One of my hobbies involves welding, and I have found these welding brushes to be really good for this.


    You can get them just about anywhere that handles hardware, tools, etc.
    Built in 1957 44,000 gallon in-ground, Wet Edge Primera Stone in Sky Blue, Intelliflo VF Pump, 600 lb. Pentair Triton II TR-100 Sand Filter, CircuPool RG 60 Plus SWG, TF-100 test kit
    If TFP has helped you, please click to SUPPORT TFP!

  10. Back To Top    #10
    techguy's Avatar
    Join Date
    Jul 2010
    Location
    Antelope, CA
    Posts
    2,687

    Re: Thought it was poop.... black algae??

    I second the idea of a smaller stainless brush, maybe even a brass brush to localize the scrubbing on the spot.

    That being said, I have vinyl so I may be incorrect.
    -- Guy --
    10K gallons in 21' Round 52 inch wall Aqualeader AG, Hayward Power Flow LX 1.5 HP pump motor, Hayward Perflex EC50AC DE filter w/Cellulose, Wide mouth skimmer, 2013 new Diver Dan (craigslist) to replace the faded old Hayward AquaBug. TF-100

  11. Back To Top    #11
    Modawg2k's Avatar
    Join Date
    May 2013
    Location
    Phoenix, AZ
    Posts
    270

    Re: Thought it was poop.... black algae??

    Quote Originally Posted by RobbieH
    Are you using a regular brush or a wire brush on the pole? It takes some elbow grease for sure!
    I'm using a smaller wire brush that attaches to the pole. I like hand scrubbing for sure.
    ~15k gallons, 3'-5'-4' Figure 8 Shape In Ground
    Wetedge Satin Matrix Interior (Pebble)
    Paramount In-floor System
    Pentair IntelliFlo VS 3050, Pentair Triton II TR100 Sand Filter
    Pentair Intellichlor IC40 SWG

  12. Back To Top    #12
    Modawg2k's Avatar
    Join Date
    May 2013
    Location
    Phoenix, AZ
    Posts
    270

    Re: Thought it was poop.... black algae??

    I'm draining the pool right now due to a high CH factor and I scraped one of the black spots and it's definitely green on the inside. Thinking about doing a chlorine wash over the areas
    ~15k gallons, 3'-5'-4' Figure 8 Shape In Ground
    Wetedge Satin Matrix Interior (Pebble)
    Paramount In-floor System
    Pentair IntelliFlo VS 3050, Pentair Triton II TR100 Sand Filter
    Pentair Intellichlor IC40 SWG

Posting Permissions

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