Tips to manage moss, algae and lichen deposits on the roof

Mariemont has a large stock of mature shade trees that overhang roofs causing a favorable environment for the growth of moss, algae and lichens with associated accumulations of dirt. I have found a simple way to remedy the problem. First, I spray the deposits and discolored areas with a weak solution of Chlorine bleach (Clorox) to kill the moss and algae. I then use a garden hose with a nozzle to spray off the residue. I have not found it necessary to use a power washer which can damage the shingles if used improperly. We welcome other ideas and suggestions.