Watermarks on concrete bullnose, how do get rid of them?


We are having our pool resurfaced but not the bullnose around too. The bullnose has watermark stains and I would like to know how to remove the stains.

q watermarks on concrete bullnose how do get rid of them
  10 answers
  • Johnavallance82 Johnavallance82 on Mar 07, 2021


    Try Acid Cleaner for Concrete, and then seal so it doesn't happen again.

  • Redcatcec Redcatcec on Mar 07, 2021

    Go to a pool supply store and ask what would work best to remove this stain on the bullnose, they probably have products in stock. It is most likely and acid product so be careful with it to not get into your eyes or on your skin, follow package directions and if you have more questions call the product manufacturer. Seal after you have done the treatment.

  • Dee Dee on Mar 07, 2021

    ill a spray bottle with equal parts white vinegar and water. Spray the water spots thoroughly with the vinegar solution, saturating them completely. Let it sit for five minutes. Scrub the stained areas with a nylon-bristled scrub brush to remove the stains.


    if it is effervescent try this To fix the problem at this point, clean the surface with a mild acid or efflorescence remover (some manufacturers make special efflorescence cleaners) followed by sealing. To avoid the problem altogether on future projects, consider using a colored curing compound or cure and seal to match the color of the concrete.

  • Robyn Garner Robyn Garner on Mar 07, 2021

    Most advice I've read says to use vinegar - some add water and/or dish soap. You are safe trying any combination of these to see what works best. High powered rinsing with your hose or a pressure washer is recommended and may work on its own.

  • Sharon Sharon on Mar 07, 2021

    If the efflorescense is a powdery white from the minerals in the mortar or the concrete rising to the surface when it gets wet, you can try just using a stiff brush. Otherwise it will take some acid, I would try the vinegar first, if that doesn't work then it will be a solution of muraic acid.... be sure to wear eye googles, heavy rubber gloves and boots, long sleeved shirt and long pants. https://www.youtube.com/watch?v=fHeipGIYsDk

  • Deb K Deb K on Mar 07, 2021

    Hi Pam,

    Vinegar Use Protective Gear with Muriatic Acid to Remove Scale from Pool Decks

    Light scale can be removed with vinegar. Mix equal parts of water and white vinegar in a spray bottle. White vinegar is a weak acid, strong enough to dissolve hard-water scale but not strong enough to ruin paint. We suggest using distilled water as it has very few minerals. Spray directly onto the scale and wait 15-20 minutes for the hard water to soften. Do not let the vinegar dry onto the scale. Wipe away with a soft, damp cloth. You may need to use full strength vinegar or repeat this process 2-3 times to completely remove the scale.

    Baking Soda

    If the scale is stubborn, try mixing a paste of 1 part vinegar and 3 parts baking soda. Apply the paste with a sponge and scrub gently, then allow the paste to penetrate for 15 minutes. Wipe the solution away with the sponge and repeat if necessary.

  • Maura White Maura White on Mar 07, 2021

    I would try something acidic like vinegar and scrub with a toothbrush.

  • Betsy Betsy on Mar 07, 2021

    Hi Pam: Usually vinegar and water, in equal amounts along with a bit of dish soap should do it. If not, Check this site:


  • Ask the company that is resurfacing what they recommend even if they aren't going to do it.

  • Vimarhonor Vimarhonor on Mar 09, 2021

    Hello. I wonder if this question might be best answered by pool experts and servicer. I wonder if a sealer might be a suggestion after servicing? It looks to be an area that’s recessed and shaded that could mold.