I know there is a product that can "reduce" the scratches or blemishes. What I do NOT know is if you can use it while fish are in there. I am sure someone will come along that can answer this question specifically. But, I know such a product exists! Good luck!
Acrylic Cleaners are O.K. to use when there are no fish in the tank, and the tank is cleaned out throughly.
I do have my doubts however at these claims that it get rid of scratches. It may be cheaper to replace the tank.
I have an acrylic scratch remover at home and it does work even inside the water with fish. I will post the name of the company tonight when i get home
Ok it called...
Acrylic Aquarium Scratch Removal Kit and it is made by Clear For Life
It does work good. It's basicly a wet sanding kit with 6 grits of sand paper the highest is 8000 grit. It is also reusable.
It cost me $29.98 US.