We're sorry to read about your disappointment with Scotts Outdoor Cleaner Concentrate and appreciate your feedback.
This product should clean most dirt, and staining from mold, mildew, and algae off of outdoor surfaces. However, if the algae or other item is green and growing, this will not destroy it or remove it from the surface. These must be destroyed first before they can be cleaned off. If using a power washer, apply the product and allow it to set before power washing the solution off the surface. With a tank sprayer, some scrubbing is necessary for the surface to be properly cleaned.
We want you to be confident in our products. For this reason, we offer a product guarantee to our consumers. At your earliest convenience, please reach out to us at 877-220-3089 if we can further assist.