I scratched my new acrylic tank multiple times yesterday while I was cleaning the front glass. And I was really stressing out about how difficult it would be to fix. I did a search on this forum and found conflicting information about posssible solutions. I thought I would share my solution for anybody else that may have the same problem. First of all it took about 10 minutes to remove 5 fairly deep scratches about 1-2 inches long each. I did not buy a scratch removal kit. I did the repairs with the tank full of saltwater. I simply bought three small pieces of wet/dry fine grit sandpaper. One 4000 grit, one 8000, and one 12000. Rub the 4,000 across the scratch. The scratch will dissappear, but the surface will look cloudy. And then rub the 8,000 across the cloudiness for about a minute, and then rub the 12,000 for about a minute. It looks brand new. The sandpaper cost me $9 and appears to be enough to last at least a couple of years. I was so scared after reading info on the internet that I would have to drain my tank to fix the scratches. This worked fine for me without disturbing the tank.