Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 11 of 11

Thread: What causes calcium carbonate to pricipitate?

  1. Back To Top    #1

    Join Date
    Aug 2010
    Location
    Lake Jackson, TX
    Posts
    130

    What causes calcium carbonate to pricipitate?

    I'm trying to understand if I'm doing something wrong. I get about 1/2 ounce or so of calcium carbonate in my polaris every 2-3 days. I tested it wit MA and it fizzles so I believe it to be CC. They are small white hard pieces. I can post a pic of a pile if it helps.

    Todays readings
    FC 4.5
    CC 0
    TA 90
    CH 270
    CYA 30
    Temp 87F
    pH 7.6
    borates 15
    salt 1400

    Thoughts?
    25000 gal IG gunite plaster. Built in spa, built 1984.
    48 SF Hayward DE-4800 filter
    1 hp Hayward super pump
    3/4 hp Polaris PB-4 booster pump, Polaris 380
    Taylor K-2006 test kit

  2. Back To Top    #2
    Mod Squad zea3's Avatar
    Join Date
    Jul 2009
    Location
    Houston, Texas
    Posts
    9,200

    Re: What causes calcium carbonate to pricipitate?

    It sounds like you could have some efflorescence occurring in the pool. Your CH is not high, nor is your pH and TA high. When CH, pH, and TA are high you may form calcium scale, which might chip off in the Polaris, but I really doubt this is what is happening in your case.
    TFP Moderator
    Helpful links: TF Test Kits,TFP Pool School, PoolMath
    Vogue 21' round AG, Pentair 1 hp 2 speed pump, 36 sq ft DE filter, Hayward S180T 150# sand filter, Houston, Texas
    Love TFP? Become a
    TFP Supporter!

  3. Back To Top    #3

    Join Date
    Oct 2010
    Location
    Pensacola, FL
    Posts
    67

    Re: What causes calcium carbonate to pricipitate?

    Undissolved salt? I had a couple of "white crystals" that were picked up a couple of days after adding..guess I didn't brush thoroughly.
    Bill Moyer
    CWO4 USN (Ret)
    Pensacola, FL
    10k gallon 12x24 in ground pool built 2008, vinyl, Pentair Intellichlor IC40, Pentair Intelliflo v/s pump, Hayward sand filter. Using the BBB method.

  4. Back To Top    #4

    Join Date
    Aug 2010
    Location
    Lake Jackson, TX
    Posts
    130

    Re: What causes calcium carbonate to pricipitate?

    I'm not familiar with efflorescence, I'll have to read up on it. I do have some mottled coloring on the walls that I suspect is scaling but I'm not sure. I was going to take a pic tonight but got tied up, I'll post tomorrow.

    I thought about salt but the only salt I've added is what's in the bleach and my number isn't very high. I also did the muriatic acid drops on the crystals and the fizzed, I don't think salt does that.
    25000 gal IG gunite plaster. Built in spa, built 1984.
    48 SF Hayward DE-4800 filter
    1 hp Hayward super pump
    3/4 hp Polaris PB-4 booster pump, Polaris 380
    Taylor K-2006 test kit

  5. Back To Top    #5

    Re: What causes calcium carbonate to pricipitate?

    If your plaster is old, it might be breaking down and coming loose. How old is it? What type of plaster? Is it plain white marblelite (calcium carbonate aggregate) type plaster? Your current CSI is a little low for plaster, and could be related if it's been low for a while.

  6. Back To Top    #6

    Join Date
    Aug 2010
    Location
    Lake Jackson, TX
    Posts
    130

    Re: What causes calcium carbonate to pricipitate?

    Here are a couple of pics showing what I'm getting. The pile of white stuff is from 2 or 3 emptyings of the polaris bag over a few days. Seems excessive to me.

    I don't know how old the plaster is, I've only had the pool 4 years but the pool is 29 years old. As far as I know it is plain white plaster, no aggregate. The picture of the bottom shows a spot worn to the gunnite, there are several of them. The plaster is a little rough in places but looks fine in most. If you look close there is a discoloration on the plaster, kind of blotchy. Scaling?

    Thanks
    Attached Images Attached Images
    25000 gal IG gunite plaster. Built in spa, built 1984.
    48 SF Hayward DE-4800 filter
    1 hp Hayward super pump
    3/4 hp Polaris PB-4 booster pump, Polaris 380
    Taylor K-2006 test kit

  7. Back To Top    #7

    In the Industry

    duraleigh's Avatar
    Join Date
    Apr 2007
    Location
    Sebring, Florida
    Posts
    30,084

    Re: What causes calcium carbonate to pricipitate?

    Well, your water looks very nice...good work!

    That does not appear to be calcium scale to me nor does it appear to be efflorescence....neither comes off into your cleaner like that.

    I think JamesW may have hit on the answer but he will have a better opinion than I after he sees the pic.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

  8. Back To Top    #8

    Re: What causes calcium carbonate to pricipitate?

    Your plaster is probably white cement mixed with calcium carbonate aggregate. Most likely, the plaster is breaking down and coming loose. Raising your CSI to 0.0 might help slow it down, but it probably won't stop the deterioration. Try scratching the plaster with something to see if it is getting soft.

  9. Back To Top    #9

    Join Date
    Aug 2010
    Location
    Lake Jackson, TX
    Posts
    130

    Re: What causes calcium carbonate to pricipitate?

    Your plaster is probably white cement mixed with calcium carbonate aggregate. Most likely, the plaster is breaking down and coming loose. Raising your CSI to 0.0 might help slow it down, but it probably won't stop the deterioration. Try scratching the plaster with something to see if it is getting soft.
    I was afraid of that. I don't really want to put a lot of money in the pool since there is a good chance we'll be moving in the not too distant future, 75 mile commute.

    The plaster seems pretty hard to me but I don't really know what soft feels like. It definitely doesn't crumble to the touch. I have been able to drill into it fairly easy though while trying to figure out if I have a budding case of black algae. Small black spots in the plaster. Haven't been able to get one of the buggers out intake enough to do the smear test.

    Looks like I should be investigating a replaster job.

    Thanks for the help.
    25000 gal IG gunite plaster. Built in spa, built 1984.
    48 SF Hayward DE-4800 filter
    1 hp Hayward super pump
    3/4 hp Polaris PB-4 booster pump, Polaris 380
    Taylor K-2006 test kit

  10. Back To Top    #10

    Re: What causes calcium carbonate to pricipitate?

    As long as it's not causing you any problems, and you are OK with the appearance, then there is no urgent need for a replaster.

    The roughness can harbor black algae, but that can usually be prevented by maintaining sufficient FC at all times, and brushing periodically.

    You might notice some clouding when brushing due to plaster deterioration. If you don't have a SWG, then you could raise your CSI to about 0.0 to + 0.2 to help reduce plaster deterioration.

  11. Back To Top    #11

    Join Date
    Aug 2010
    Location
    Lake Jackson, TX
    Posts
    130

    Re: What causes calcium carbonate to pricipitate?

    I have noticed clouding when I brush. It settles back to the bottom fairly quick. Thanks for you input James
    25000 gal IG gunite plaster. Built in spa, built 1984.
    48 SF Hayward DE-4800 filter
    1 hp Hayward super pump
    3/4 hp Polaris PB-4 booster pump, Polaris 380
    Taylor K-2006 test kit

Posting Permissions

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