10 Best Roof Algae Cleaners 2025 in the United States

Wet & Forget Outdoor Moss, Mold, Mildew, & Algae Stain Remover is a versatile multi-surface cleaner designed to easily attach to a garden hose. It uses a unique nozzle that can spray up to 30 feet, making it ideal for cleaning roofs and high areas like second-story siding. This product is quite user-friendly as it requires no scrubbing, rinsing, or pressure washing—just spray it on and let nature do the work. This is particularly convenient for those who prefer a low-effort cleaning method.

The cleaner works over time, with green stains typically disappearing within 1-2 weeks and more stubborn black stains taking several months to clear. It boasts a long-lasting effect, keeping surfaces clean for up to a year or longer. It’s essential to note that its cleaning action is gradual and may not offer immediate results for heavy stains. The product is bleach-free and non-acidic, making it safer for use around plants when precautions are followed. However, it is advised to keep it away from water sources like rivers and ponds.

It treats up to 2,000 square feet, though heavily stained or porous surfaces may require more product. Customer reviews are generally positive, with a 4.4 out of 5-star rating from over 1,200 users, highlighting its effectiveness and ease of use. On the downside, the cleaner is not instantly effective on all types of stains and may take up to a year for long-established ones to disappear. Additionally, environmental precautions must be strictly followed to avoid harming aquatic life.

The Wet & Forget Outdoor Moss, Mold, Mildew, & Algae Stain Remover is designed to tackle green and black stains on various surfaces, including roofs, with its new and improved nozzle. The hose-end attachment can spray up to 30 feet, offering convenience for reaching higher areas. The product doesn't require rinsing, making the application straightforward. It's important to apply it on a dry surface during cool weather and ensure there’s no rain forecast within 4-5 hours.

The initial cleanup for green stains happens within 1-2 weeks, while more stubborn black stains may take several months. Long-established stains could take up to a year to clean, but surfaces can stay clean for a year or more afterward. This bleach-free and non-acidic formula is safe for use around plants, provided they are flushed with water before and after application, although you should avoid spraying near bodies of water.

The product treats up to 2,000 square feet and has an unlimited shelf life, making it a cost-effective option for heavy stained and porous surfaces. The effectiveness duration on extremely stubborn stains may require patience, and environmental precautions are essential to avoid potential harm.

The 30 SECONDS Mold and Mildew Stain Remover offers a convenient solution for removing organic growth stains such as algae, mold, and mildew from outdoor surfaces. Its ready-to-use formula and battery-powered spray wand eliminate the need for pressure washing or mixing, making it an excellent DIY option for home improvement enthusiasts. Users can expect immediate results on various surfaces, including decks, siding, and bricks, which may appeal to those dealing with algae on their roofs.

The product is designed to be safe for plants and lawns when used as directed, highlighting its environmentally friendly nature. User feedback is generally positive, with an average rating of 4.3 out of 5 stars from 586 reviews, indicating satisfaction with its performance and ease of use. It's ranked #61 in Household Mold & Mildew Removers, suggesting reliability within its category.

This product is ideal for those looking for a quick, easy-to-use cleaner that doesn't require additional tools or preparations.