Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 6 of 6

Thread: Differences in Sequestrants

  1. Back To Top    #1

    Join Date
    Jul 2007
    Location
    Hillsborough, NC
    Posts
    515

    Differences in Sequestrants

    In a final effort to get the yellow out of my water, I tried a third brand of sequestrant/chelating agent, Sequa-Sol It worked. The water is the best looking it has been to date. The previous two were Metal Free and Sea Klear Metal Klear. The MSDS on this new one says the active ingredient is Sodium Citrate. It is listed as a chelating agent where the previous two used Acrylamide-Acrylic Acid Copolymer, listed as a sequestrant. I can't find much that explains the difference, at least as it pertains to pools. I am trying to understand why this worked and the metal free that worked last year didn't this year. Does groundwater change that much year to year?
    27' Round Might Sun AG Pool 18000 Gallon Intex Krystal Clear SWG Hayward Pump/Filter on a Timer

  2. Back To Top    #2
    Guest

    Re: Differences in Sequestrants

    MetalFree uses EDTA as the chelating agent. I have corresponded with Naturalchemistry about their choise of EDTA since it has a high chelaton index for calcium. I suspect the SeaKlear product is similar since I know it is not phosphanate based but I do not have a MSDS for it so I am not sure what is in the Seaklear. Both of them are 'phospate free' and not that effective. Sequa-sol by GLB uses phosphonic acid derivatives, most likely HEDP, just like the Jack's Magic products and Proteam's Metal Magic. I am looking at the MSDS for it as I type this. It does list sodium citrate but in the box above it says CAS Number: Not Established
    Chemical Family: Phosphate
    Chemical Formula: Proprietary Mixture
    The MSDS is not necessisaily the ingredient list. By stating it's a proprietary mixture they can get around what is actually in it but by saying the chemical family is phosphate then it means it's a phosphonate since that is the main group of phosphate based sequesterants and HEDP is the most common one used in pools. The phosphonate based ones are also the effective sequestarants.
    The Acrylamide-Acrylic Acid Copolymer is actually a polymeric clarifier. It's main purpose is to keep the water from clouding since sequesterants can cause the water to cloud if calcium levels are high.

  3. Back To Top    #3

    Join Date
    Jul 2007
    Location
    Hillsborough, NC
    Posts
    515

    Re: Differences in Sequestrants

    Quote Originally Posted by waterbear
    MetalFree uses EDTA as the chelating agent. I have corresponded with Naturalchemistry about their choise of EDTA since it has a high chelaton index for calcium. .
    In layman's terms - albeit a bit simplistic - (and just to make sure I understand what I've read so far) this means the EDTA likes the calcium a bit more than it likes the metals, hence the ineffectiveness in my water? I want to understand why what I did works so I can repeat it next time.

    With a vinyl pool, is there a reason I should test for calcium? I haven't been since what I read says it is a concern for concrete pools.

    thanks for the explanation. It helped a lot.
    27' Round Might Sun AG Pool 18000 Gallon Intex Krystal Clear SWG Hayward Pump/Filter on a Timer

  4. Back To Top    #4
    Guest

    Re: Differences in Sequestrants

    Quote Originally Posted by crokett
    Quote Originally Posted by waterbear
    MetalFree uses EDTA as the chelating agent. I have corresponded with Naturalchemistry about their choise of EDTA since it has a high chelaton index for calcium. .
    In layman's terms - albeit a bit simplistic - (and just to make sure I understand what I've read so far) this means the EDTA likes the calcium a bit more than it likes the metals, hence the ineffectiveness in my water? I want to understand why what I did works so I can repeat it next time.
    Exactly!
    With a vinyl pool, is there a reason I should test for calcium? I haven't been since what I read says it is a concern for concrete pools.
    Calcium is a concern for ALL pools. You need to KNOW what your CH is because it ia component of just about all fill water and it will interact with your other water balance paramaters. Calcium is not needed to protect the pool surface in a vinyl pool but knowing where your CH is sitting is something that you should know. If your calcium is high and you add baking soda you could end up with a cloudy mess, particularly if your pH is on the high side. If your water is VERY soft then your pool might have a tendency to foam a bit, particularly if you have a higher than normal bather load. IMHO, CH for a vinyl pool should be a bit above 100 ppm minimum.
    thanks for the explanation. It helped a lot.

  5. Back To Top    #5

    Join Date
    Jul 2007
    Location
    Hillsborough, NC
    Posts
    515

    Re: Differences in Sequestrants

    Thanks Waterbear! I will start testing calcium again. IIRC I tested once at the beginning of the season and from the ground the water was at 120 PPM but I will retest.

    On a side note, my neighbor's well is about 300' from mine but it is a few hundred feet deeper so he may be on a different aquifer.. As far as I know he has no problems with discoloured water. Can groundwater conditions vary that much?
    27' Round Might Sun AG Pool 18000 Gallon Intex Krystal Clear SWG Hayward Pump/Filter on a Timer

  6. Back To Top    #6
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: Differences in Sequestrants

    Ground water can vary dramatically over short distances both horizontally and by depth. Often enough entire areas will be similar, but it isn't always that way.
    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

Posting Permissions

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