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  • Wendy Purser March 2, 2012 at 7:57am

    I have found that ascorbic acid works the best for me on iron stains.

     

  • Rob Lane March 1, 2012 at 9:41pm

    Thank you.

  • Bill Nash March 1, 2012 at 4:22pm

    Rob, Two years later and we're still discussing the same problem, very unusual. Gray stains are iron and tan are copper. On concrete or gunite pools with a fiberglass laminate, the stains are always the result of an over abundance of metals in the water. The following applies only to fiberglass, be it a fiberglass pool manufactured in a factory, or a laminate made with fiberglass, vinyl ester resin, and swimming pool gel coat, using an existing concrete or gunite pool as the mold.

    The problem is that the metals are too small to be removed by the filter. The solution is really quite simple (as I mentioned in my two previous replies). By using a sufficient quantity of any sequestering agent, the metals will be clumped together in sufficient size to be removed by the filter. We have solved this very common problem hundreds, if not thousands, of times over the past 13 years. In my previous replies (above), I provided more information about the cause and the solution. These instructions are not theoretical, and, if followed, will permanently resolve this problem. Bill Nash

  • Rob Lane February 28, 2012 at 10:30pm

    Last fall, I tried a Stain and Scale. It worked well. The surface improved. I have used Omni Filter Aid in the past. With gutters instead of skimmers, it is tougher to get the F.A. to the sand bed. I have been told that the F.A. will catch the metals and backwashing disposes of them. What have you done?? Spring is coming. :)

  • David McLaren February 27, 2012 at 12:41pm

    Once you get the metal off the walls and back into the water, you need to eliminate them from the water.  Have you tried a metal eliminator?  That is the only way to get rid of the metals.

  • Bill Nash December 18, 2011 at 2:28pm

    Mark,

    I have found that applying muriatic acid directly onto the fiberglass laminate does more harm, over the long term, than it does good. True, it will probably remove the stain temporarily, but the stain will return and, in the meantime, the swimming pool gel coat (finish coat) will be seriously damaged.

    You are absolutely correct regarding the sequestering agent. By using the appropriate amount, based on gallons, and running the pump for 24 hours continuously, all the gray or tan stains will disappear. However you must still deal with the cause of the staining, or it will surely return.

    Nevertheless, there are some stains that are not caused by total dissolved solids (TDS). A good example is chlorophyll stains caused by droppings from trees, i.e. leaves, branches, and twigs. Usually these stains are smaller but far more difficult to remove. But, I should point out that "they can be removed", but not under any condition should muriatic acid be used.

    Regarding my reply of April 9, 2011; I listed 3 reasons why a sequestering agent will nearly always be required. There is a fourth reason which I neglected to add: creek water. -Bill


     
    Mark H. Caldwell said:

    If the stains are metal, we normally put a man in the pool with a squirt bottle of muriatic acid.  put the bottle on top of the stain and apply the acid directly onthe stain.  In most cases the the metals will come off the fiber glass.  Some times metals will just stick to the fiber glass.  You can brush it all you like and it will not budge, but if you wipe it with a wet towel the metal will come off the fiberglass and back into the water.  You will need to add a sequestering agent to remove the metals for the water.
  • Bill Nash April 9, 2011 at 3:38pm

    A couple questions need to be answered regarding the age and condition of the top coating (gel coat). Let's assume, for the purpose of this discussion, that the laminate was recently installed (just to rule-out natural degradation of the gel coat over a period of ten or more years).

    In this instance, the staining is equal over numerous, but not all, sections of the pool. There are three possibilities:

    1. A heater with iron headers and impellers. Have them switched-out by a pool service pro.
    2. The pool was filled with "well water" or by the local fire company.
    3. Excessive rain.

    The second and third possibility's are the result of too much iron in the water. Testing strips are worthless in this instance. The water must be tested at a testing facility for: total dissolved solids (TDS). Or, don't even bother with the testing because the results will show too much metal (iron) in the water.

    The solution is easy and inexpensive. The iron is too small and too dispersed for your filter to remove. Purchase a "sequestering agent" from a reliable company (we use "jacksmagic.com"). The amount of the chemical will be determined by the size of the pool, i.e. gallons of water.

    Pour the required amount of sequestering agent into the "filled" pool, and run the pump for 24 continuous hours. The stains will disappear. This also applies to the heater possibility, after the headers and impellers are changed.

    Always keep some sequestering agent on-hand. Excessive rain or new pool water will require the same treatment. If anyone is interested, we can continue this discussion for "older" fiberglass laminates. -Bill

  • Don Parish January 6, 2011 at 7:17pm

    Rob,

    It always helps to know what you are treating.  I would suspect you have a copper stain, but have you checked the stain with a Jacks stain ID kit or a vitamin C tablet.  If the vitamin C takes it off a simple combination of stain remover and sequestering agent will work to remove the stain and the metals from the water.

  • Mark H. Caldwell January 6, 2011 at 12:57pm
    If the stains are metal, we normally put a man in the pool with a squirt bottle of muriatic acid.  put the bottle on top of the stain and apply the acid directly onthe stain.  In most cases the the metals will come off the fiber glass.  Some times metals will just stick to the fiber glass.  You can brush it all you like and it will not budge, but if you wipe it with a wet towel the metal will come off the fiberglass and back into the water.  You will need to add a sequestering agent to remove the metals for the water.
  • Jack May 23, 2010 at 3:46am
    Rob,
    I would suggest you add a stain and scale product first. Many times with fiberglass this will remove the stains without having to add an additional stain remover. Make sure you add a sufficient amount and price is an indicator of quality or strength.
    Jack
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