Very Very good video Pat. You might want to re consider using the word BLEACH ? We NEVER mention bleach, here is why. It Cheapens the value of the roof cleaning. Every time we memntion bleach, the customer says "what do you mean 450.00, to spray some bleach on my roof" ??? Use ARMA approved, and when asked What you use, say "We use Trisodium phosphate and sodium hypchlorite", NEVER say Bleach!