This roof had bad black stains (gleocapsofmagma) that were penetrating the shingles on the roof, along with some moderate mold & algae which is typical for these types of roofs. We used our soft wash system which is low pressure so we do not damage anything while we are cleaning the roof. (You never want to use pressure while cleaning roofs.) So our soft wash system allows us to put our roof wash solution evenly across the whole roof, so that the solution will kill any mold or algae.