How to get rid of algae on the roof you could replace all the roofing with new shingles dark enough to disguise the staining or with shingles laced with copper granules which are lethal to algae.
How to get moss off roof youtube.
Use the tool to gently lift away matted moss that has gathered on the flat sections of the shingles.
In the seams use the sharp edge of the scraper like a dental pick to force out the moss.
But that would only make sense if the shingles were worn out.
As seen on amazon.
Climb up to the roof and begin scraping off dead moss from the shingles using a putty knife or painter s 5 in 1 tool and working from the bottom up.