 So a little trick of the trade there. Use a roof cleaner and then a piece of copper flashing installed into that ridge will give you some ongoing protection against future streaking. That is a cool idea about the copper. Spray and forget. Do I just use my regular hose? The spray and forget is a concentrate, so all you need to do is mix it up. And what you can use to apply it really depends on what you have. What I like to use is kind of a pump-up garden sprayer. It's really easy to handle. It doesn't get too heavy. And then I spray my roof down with that.