This product is amazing. I used it to clean copper pots that had a lot of buildup because I had been too lazy to polish them. I soaked the pots for a week and the mess just wiped away.

Had our pristine Trophy Pro in Puget Sound Saltwater for three weeks and took off all of the crud and looks new again. Required several applications and some scrubbing but worked better than other products we've tried and is safe for environment. We tried Qt. and Used about 16oz. so will need more and recommend buying larger amount if you have boat with severe crud and/or bigger than 21'. I will purchase gallon and use garden type sprayer to make it easier than the provided spray bottle which it wasteful and doesn't apply widely. Noted some spotting on the aluminum boat trailer from dripping - no big deal to me but just be aware.

I recently bought a used boat. The hull had a lot of crud build up on it. Since it was a white hull it was easy to see the crud. Tried several hull cleaners, even some household cleaners, nothing worked didn't even appear to take any of it off. Tried the Bio-Kleen Fiberglass Cleaner even though it took a few applications it cleaned the crud right off. Basically just sprayed it on let it sit a few minutes then wiped it down. Yes it took a little elbow grease but it cleaned the dirt.

Now that its clean, I just spray the fiberglass cleaner on the hull when I pull the boat out and simply wipe it down, it takes all the crud off and no chance of build up. I recommend this product to boat owners. Going to try some of the other cleaners they offer around the house.

I just finished using this product on my pontoons. I was uncomfortable with the review that stated "left pontoons white" I found that they came so clean on certain angles they appeared white. My wife would be the first one to pick out an issue and when she stated they look like new I was extremely pleased. They do look like new and they look almost as new from the factory. I found that the application is not as easy as the video. It is up to you on how much effort you want to put behind your work. Learnings: I first power washed the pontoons and decided to work under the deck in case of the "white" outcome. Shortly after power-washing I applied the product following the instructions. This took a bit of elbow grease, a sponge that had a fine Scotch Brite on one side, and a second application ( the brush was not working well). The next day (after pontoons were dry), I started on the outside of boat. I applied the product using a new sponge with the same Scotch Brite pad. It was difficult to move the sponge at first until is became saturated. I did a 4 foot section at a time, unlike the previous day doing the entire length at one time, and had a bucket of hot water, unlike the previous day, with tight woven pores. After agitating the 1st 4' foot section, I applied the product to the 2nd 4 foot section, went back to the 1st section and wiped with the tight woven sponge and hot water leaving a heavy amount of suds behind. I continued this process for the remainder of the pontoon and with the suds left behind and wet, did the entire length of the pontoon with the Scotch Brite sponge. Once finished I power-washed the pontoon and it came out great. A 2nd application was not needed and the residue came off much easier than the day before process. I couldn't be happier. Tomorrow 10/8/14 I am going to use the Alumna-Clean and I'm hoping it is basically a put on wipe off application. I really do not need this 2nd step but since I still have a little black residue in couple of spots and I have the product, I'll give it a shot. In the spring it is my intention to use polish and if someone can tell me which of the products is easiest to use I would be most appreciative. The toons look great and the tech support was wonderful. (spoke to them prior to even starting the process when ordering) So again for learning: Power-wash, let dry over night, follow the instructions, keep toons sudsy until completion, use Scotch-Brite fine sponge, plan on spending some time depending upon the look you want to achieve, then power-wash off. The 2nd day was much easier then the 1st!!

Bio Kleen Fiberglass Cleaner - Hull & RV Cleaner (M006) is the best I have ever used for cleaning water line stains off my boat..Spray on, brush, let stand for 10 minutes, rinse, and the stain is gone!