+ Reply to Thread
Results 1 to 8 of 8

Thread: Concrete pool - Black spots (Maybe Algae) ??? Need Help

  1. #1
    Join Date
    Apr 2012
    Location
    Panama City Beach, Fl
    Posts
    34

    Default HELP - Concrete Pool Black Algae

    Post is edited.

    so I did a little more research and found out I do in fact have black algae. I live about 10 minutes from the Gulf of Mexico, and people often stop by and visit on their way home from the beach. I looked at pictures online of black algae, and it looks identical.

    So I am not asking what I have anymore but more so how to get rid of my black algae.

    I read to do a triple amount of normal shock, and brush the hell out of the pool with a stiff brush. Adding Leslie Black Algae remover will help.

    Question - should I use a metal brush, or just stiff bristle brush?

    Question - is the Leslie Black algae remover worth it? Any other alternatives?

    thanks for the help everyone.
    Last edited by Wraypau; 05-28-2015 at 03:00 PM.
    In Ground, 6,900 Gallon Gunite pool with tile trim, Haywayd EcoStar SP34000VSP Variable Speed, Aquarite 25k SWCG, North Florida

  2. #2
    Join Date
    Jul 2013
    Location
    Northern Illinois
    Posts
    816

    Default Re: HELP - Concrete Pool Black Algae

    Here's something that Ben wrote once. "... to firmly determine what the spots are, swim down, and scrap the spot with your fingernail. If the spot IS black algae, you'll end up with a bit under your fingernail. Swim up, and smear the algae on a bit of white cardboard or the unlined side of an index card. Black algae will look almost black, but will smear dark green."

    I would recommend running this test first.
    26K gal 20x40 rectangular IG vinyl pool; Apr 2014: New pump, liner, auto-cover, & water; Pentair Whisperflo 1HP pump; Pentair Trition sand filter; Cover/Star CS-500 auto cover; Taylor K-2006C; OTO

  3. #3
    Join Date
    Apr 2012
    Location
    Panama City Beach, Fl
    Posts
    34

    Default Re: HELP - Concrete Pool Black Algae

    Its definitely black algae. Did the fingernail test. How do I get rid of this algae.
    In Ground, 6,900 Gallon Gunite pool with tile trim, Haywayd EcoStar SP34000VSP Variable Speed, Aquarite 25k SWCG, North Florida

  4. #4
    Join Date
    Jul 2013
    Location
    Northern Illinois
    Posts
    816

    Default Re: HELP - Concrete Pool Black Algae

    A quote from Ben:

    (Get) your pH between 7.2 and 7.8, your alkalinity below 140ppm, and know what your stabilizer is, use the "Best Guess" chart... to determine the CORRECT chlorine levels for your pool.

    Once you've done all that, adjust chlorine to shock levels AND use your brush. Continue doing so (chlorine AND brushing) for 1 week AFTER all visible algae is gone.

    Then, make sure you MAINTAIN adequate chlorine levels for your stabilizer level.

    Meanwhile, if you can get some calcium hypochlorite shock, and then BRUSH the spots, followed by sprinkling them with cal hypo, that will help.
    26K gal 20x40 rectangular IG vinyl pool; Apr 2014: New pump, liner, auto-cover, & water; Pentair Whisperflo 1HP pump; Pentair Trition sand filter; Cover/Star CS-500 auto cover; Taylor K-2006C; OTO

  5. #5
    Join Date
    Apr 2012
    Location
    Panama City Beach, Fl
    Posts
    34

    Default Re: Concrete pool - Black spots (Maybe Algae) ??? Need Help

    Thanks for advice. One more quick question, what is proper chlorine level?
    In Ground, 6,900 Gallon Gunite pool with tile trim, Haywayd EcoStar SP34000VSP Variable Speed, Aquarite 25k SWCG, North Florida

  6. #6
    Join Date
    Jul 2013
    Location
    Northern Illinois
    Posts
    816

    Default Re: Concrete pool - Black spots (Maybe Algae) ??? Need Help

    It depends on your tested CYA level. See: http://poolsolutions.com/gd/best-gue...e-chart.html#a
    Read it and focus then on the Best Guess Chart.

    I know you have a K- 2006 and have been around the block. So you must know that if your CYA is in the high end of the range, bump the shock level FC accordingly.

    If you need help, report your CYA. We will be happy to help with mor specific recommendations!

    Best wishes
    Last edited by FormerBromineUser; 06-21-2015 at 01:21 AM.
    26K gal 20x40 rectangular IG vinyl pool; Apr 2014: New pump, liner, auto-cover, & water; Pentair Whisperflo 1HP pump; Pentair Trition sand filter; Cover/Star CS-500 auto cover; Taylor K-2006C; OTO

  7. #7
    Join Date
    Apr 2012
    Location
    Panama City Beach, Fl
    Posts
    34

    Default Re: Concrete pool - Black spots (Maybe Algae) ??? Need Help

    I took out my 2800 psi pressure washer, put on the 15 degree tip, and pressure washed the walls. (yes, the pool was still full of water, so you just hold the tip about 1 inch fro wall) and it blew all the black algae off the wall and out of the cracks, then I shocked the hell out of the pool for about a week, and man o man, it made a huge difference.
    In Ground, 6,900 Gallon Gunite pool with tile trim, Haywayd EcoStar SP34000VSP Variable Speed, Aquarite 25k SWCG, North Florida

  8. #8
    Join Date
    Jul 2013
    Location
    Northern Illinois
    Posts
    816

    Default Re: Concrete pool - Black spots (Maybe Algae) ??? Need Help

    Excellent to hear!!! Woot!!!!

    PoolDoc always warned that black algae is very difficult to eradicate in a plaster pool. Keep an eye out for any recurrence.
    26K gal 20x40 rectangular IG vinyl pool; Apr 2014: New pump, liner, auto-cover, & water; Pentair Whisperflo 1HP pump; Pentair Trition sand filter; Cover/Star CS-500 auto cover; Taylor K-2006C; OTO

+ Reply to Thread

Similar Threads

  1. Black algae, DE & sand filter, proper brush for old concrete
    By mauisal in forum Dealing with Algae & Slime
    Replies: 1
    Last Post: 08-02-2015, 05:02 PM
  2. Black Spots on bottom of pool
    By PoolNewbies in forum Dealing with Algae & Slime
    Replies: 4
    Last Post: 06-25-2013, 09:27 AM
  3. Black spots on bottom of pool??
    By cbaird in forum Dealing with Algae & Slime
    Replies: 6
    Last Post: 06-02-2013, 01:20 PM
  4. Black Spots
    By dockstock1011 in forum Pool Chemicals & Pool Water Problems
    Replies: 1
    Last Post: 08-13-2012, 11:36 AM
  5. Recurring (and increasing) Black algae spots on Fibreglass pool
    By grannie14 in forum Pool Chemicals & Pool Water Problems
    Replies: 4
    Last Post: 07-11-2012, 10:27 PM

Bookmarks

Posting Permissions

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