There are 2 ways you can apply D/2:
D/2 works with the elements. Results occur within 1-4 weeks, depending on severity of stain.
D/2 continues to work over time and optimal results are often seen years after spraying.
After initial treatment a once-a-year light spraying will help maintain a clean, stain-free surface.
NOTE: Heavy biological deposits can be loosened using a low-pressure washer (600 psi) and may require repeat applications of D/2 to achieve complete cleaning after detachment. Alternatively, heavy growth can be detached by manual scraping using wooden or plastic tools immediately after application.