Secondary Hydration (Halos)


Testing is always recommended prior to any cleaning project. Although this process has been tested and proven effective, every situation is different and can present different challenges. Allow the test area to dry thoroughly before evaluating the final results

Secondary Hydration or “Halos” can be present before pavers are installed. Cleaning after installation can remove these unsightly stains and restore the pavers to their natural color!

  • 1. Lightly pre-wet (do not soak) the paver surface.
  • 2. Apply NMD 80 through an EC Jet for Pavers (or a pump sprayer diluted 4:1) using overlapping strokes to achieve even coverage. Allow the product to dwell for 5 to 7 minutes. Do not allow the product to dry on the surface.
  • 3. While the NMD 80 is dwelling, apply White Scum Presoak through an EC Spray or pump sprayer using a cone shaped nozzle only to the areas where secondary hydration or halos are present.

    * Multiple applications of White Scum Presoak may be required to completely remove stains.

    * Do not rinse in between

  • 4. Re-apply NMD 80 through an EC Jet for Pavers (or a pump sprayer diluted 4:1) to restore the appropriate color (presoaks can whiten the color).

    * With NMD 80, the longer it stays on the paver surface, the cleaner the end results.

    * It has been noted that longer dwell times produce a decrease in the water rinse.

  • 5. Begin rinsing from the highest elevation to the lowest. Use long, even strokes that overlap each other. Low pressure rinse is recommended through the EC Jet (turn off the soap valve and rinse). If a pressure washer is unavailable, a garden hose may be used.

    * When using a pressure washer, a wide tip nozzle is suggested.

    * Care should be taken near the joints not to “blow” the sand out.

  • 6. If there are still spots with secondary hydration present after rinsing, repeat steps 3 and 4 just to the areas where they are still visible. Thoroughly rinse again to remove remaining stains and chemical.