I use it on my fiberglass boat hull to remove yellowing below the water line. Spray on, rinse off. I use it on my shower stall (well water) to remove yellowing from iron in water. I use it on my deck (Trex) to remove rust from well water drips. And on my vinyl fence posts to remove well water stains from watering plants.

Had to get a 29 Searay that wasn’t well taken care of buffed out on top in a 4 day period. Called up the company, and it was actually a person. Super impressed by service, and super impressed by their products. Took the oxidation right tf off.

The scum line on my boat was about 7 years old. I had used the acid products in the past to remove the scum but due to their harsh nature and the fact that they are awful for the environment made me decide to live with the dingy brown line.

Then I saw the Biokleen video on YouTube and it seemed too good to be true. The price was so reasonable that I though "What do I have to loose?" Got the product and just as in the video I sprayed it on, brushed it, and hosed it off and my boat was back to it's original luster. Thank God! One of the most amazing products I have used.

Used it on our new but used boat that use to sit in the lake its whole life. It removed most of it there is still a hard water line but not as noticeable.

Very impressed with with how well it works and how easy it is to use . Great product !