Use a soft cloth and pool water to clean your vinyl pool liner once a week. To remove more stubborn dirt, algae and stains, use a brush to gently scrub the liner above and below the waterline. Don’t use harsh, acidic chemicals or abrasive materials such as steel wool. You can also add a vinyl liner cleaning solution to the pool water to prevent staining from sunscreen, body oils and other contaminants that collect at the waterline.