Stone sculptures are vulnerable to biological staining caused by algae, moss, lichen, and other microorganisms. These stains not only mar the appearance but can also degrade the stone over time. Here are the most effective ways to prevent and combat biological staining:

1. Regular Cleaning – Gently wash sculptures with a soft brush and mild detergent to remove dirt and organic debris that promote growth. Avoid harsh chemicals that may damage the stone.

2. Use Biocides – Apply eco-friendly algaecides or fungicides to inhibit microbial growth. Reapply as needed, especially in humid climates.

3. Protective Coatings – Sealants like siloxane or fluoropolymer coatings create a water-repellent barrier, reducing moisture retention that fosters biological growth.

4. Proper Placement – Position sculptures in well-ventilated, sunny areas to minimize dampness. Elevate them slightly to avoid ground moisture absorption.

5. Manual Removal – For existing stains, carefully scrub with a plastic scraper or stiff brush. For stubborn growths, a diluted vinegar or hydrogen peroxide solution can help.

6. Routine Inspections – Check sculptures seasonally for early signs of staining. Prompt treatment prevents deeper penetration and long-term damage.

By combining these methods, you can preserve the beauty and longevity of stone sculptures while keeping biological staining at bay.