Tallahassee in Florida at degree lattitude. Roof at 30 degree tilt. At roof edge 8 feet above ground. 3 rows of sanyo 215 pannels 13 panel in top and bottom row 14 in middle. The length of panels is 186.6 inches from top to bottom (=62.2*3). How shall I clean panels, during spring and summer, probably once a week if there is no heavy rain.