What is the best thing to clean shingles with?

The best thing to clean shingles with is a shingle-safe, low-pressure method that removes algae, moss, and dirt without stripping granules or voiding the warranty. Shingle manufacturers like GAF, Owens Corning, and Atlas recommend using oxygen bleach, sodium percarbonate, rather than chlorine bleach or pressure washing. A proven homemade solution is one gallon of water mixed with one quart of oxygen bleach and a quarter cup of mild dish soap, applied with a garden sprayer from the ridge downward, allowed to sit for 15 to 20 minutes, and then gently rinsed with low-pressure garden hose water, never a pressure washer. For those preferring commercial products, Roof Shampoo, Spray and Forget, and Wet and Forget Outdoor are widely regarded as safe and effective, as they kill algae and moss gradually without harsh chemicals and require no rinsing. For moss specifically, potassium salts of fatty acids or zinc sulfate based products like Moss B Ware work well. The best approach also includes preventive measures after cleaning, such as installing zinc or copper strips near the ridge, trimming overhanging branches to increase sunlight, and keeping gutters clean. Always protect landscaping by soaking plants with water before and after application, wear non-slip shoes, and work on a cool, overcast day to prevent solution from evaporating too quickly.