Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 4 of 4

Thread: Is this Algae or metal staining, or what? (pictures attached)

  1. Back To Top    #1

    Join Date
    May 2014
    Location
    Southern California
    Posts
    17

    Is this Algae or metal staining, or what? (pictures attached)

    After joining this great forum a week or so ago I'm beginning to find that all of the advice I've been given on my pool in the past by various folks is full of ****...So, i bring another question that maybe someone here can help answer. Can anyone tell me if the stains on the bottom of my pool are "Algae" (some kind or another), or are they "metal" staining absorbed by the poorly mixed plaster as what I was previously told. (and that a re-plaster would be the answer to fix that)

    I'm in the process of currently lowering my CYA (working on a partial or full drain), so I can properly sanitize with lower FC and wanted to know if i should be looking at re-plastering, or just looking at doing a SLAM to get rid of this. (if it's algae)

    Picture of Steps



    Deep end side



    Shallow end of pool



    Full shot of pool



    Thanks in advance for reading!
    20K gallon, IG plaster pool in Southern CA.- built in 1963. 1HP single speed pump with DE filter, (using fiber substitute) - mainly in full sun; no heater.

  2. Back To Top    #2
    Richard320's Avatar
    Join Date
    Jan 2010
    Location
    San Dimas, CA (LA County)
    Posts
    18,768

    Re: Is this Algae or metal staining, or what? (pictures attached)

    That first picture looks like plaster delaminating to the right of the stains. To fix that, you're looking at a replaster.

    To ID the stains, set a cheap Vitamin C tablet on one of the brown stains for ten minutes or so, then remove it. If you have a white spot where it was, it's metals.

    If the stained areas feel raised and rough, it's Calcium scale thanks to hard water, high evaporation, and high pH not kept in check.
    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.
    A pool is like a pet - you have to feed it every day, even the days you don't want to play with it!

  3. Back To Top    #3

    Join Date
    May 2014
    Location
    Southern California
    Posts
    17

    Re: Is this Algae or metal staining, or what? (pictures attached)

    Quote Originally Posted by Richard320 View Post
    If the stained areas feel raised and rough, it's Calcium scale thanks to hard water, high evaporation, and high pH not kept in check.
    I'm pretty sure it's raised and rough. My calcium levels are through the roof so this doesn't surprise me...if I lower the total calcium level (with a partial or full drain) will these go away or can you recommend a treatment option?

    Also..why are they brown? I thought calcium would be white
    20K gallon, IG plaster pool in Southern CA.- built in 1963. 1HP single speed pump with DE filter, (using fiber substitute) - mainly in full sun; no heater.

  4. Back To Top    #4
    Richard320's Avatar
    Join Date
    Jan 2010
    Location
    San Dimas, CA (LA County)
    Posts
    18,768

    Re: Is this Algae or metal staining, or what? (pictures attached)

    An acid wash or a no drain acid wash or a drain and sandblast will get rid of the Calcium scale. Any of those options will weaken your plaster.

    Then there was this. I didn't do this, I'm just posting the link.

    The brown is probably from dirt or rust or decayed-leaf-tea that was in the water when the stuff started sticking. Impurities embed within crystals easily. Even with sparkling clear water, Calcium scale is sort of a tannish-grey color, not gleaming white like movie-star teeth.
    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.
    A pool is like a pet - you have to feed it every day, even the days you don't want to play with it!

Posting Permissions

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