Well I have a EPDM Roof to clean that has not been cleaned in 8 years and there is a ton of algae,lichen, and dirt.  What do you think the best chemical ratio and checmicals are?  I do not have any green wash or anything in this line yet. I have used regular roof mix for these in the past, but was thinking with how filthy the roof was maybe someone would have a better suggestionns?  Using an All-flo pump to apply my mix.  I am aware that this will take a few applications, but wanted to see what would work best.  Thanks in advance.