Bests & Worsts Reviews from Amazon

I really hate the algae stains on my roof. I learned about this product through Internet research and was elated by the good reviews. In October of 2011 I applied the first treatment. I bought a backpack sprayer (from Amazon - where else?) and followed the instructions EXACTLY. I want to empahsize that I am a very meticulous person and was precise in the mixing and application. So I waited for the amazing results and my roof without black streaks. And I waited ..... and I waited... and my family was making fun of me because I would ask every few weeks if they looked fainter .... and I waited. So being a patient fellow, I decided with all of these great reviews that I must have done something wrong or maybe had a bad "batch". So on June 29, 2012 I applied the second treatment of the magical elixir. It is now almost the beginning of December and I am ticked everytime I come up my driveway to see the black stains on my roof. I am now researching other methods of ridding myself of the dreaded algae. Oh and I also used it on the sides of my enclosed car trailer to see if it would remove the black streaks that have built up over the years. Same result. Nothing. I don't like to write bad reviews and have held off because I am flumoxed by the amount of good reviews and was waiting for the magic to happen but the joke's on me. Don't waste your money or time on this stuff. It's dreadful. 12/1/2012 - Update - I posted the same review on their Facebook page and they told me to call them. They were very concerned and customer oriented and told me they would send new product no charge with instructions on how to increase the strength. I will apply and update the review. 07/13/2013 - Used the new instructions to apply to the roof with increased strength. Little to no positive results. I wanted the black algae to be gone. It's still there. Don't bother with this stuff for your roof.