If the tank is scratched form the outside yes, you can use various compounds and methods to remove or reduce the scratching, however a alot of times during this process its also possible to create a worked in optical illusion where the scratches were, which can actually be more of a eyesore than the scratch was itself as they tend to make a ot of distortion........Scratches n the inside would alsmost dictate a tank drain down.
I think anytime a material like glass or acrylic is bent or formed its gonna make optical illusions. My glass bowfront makes it appear to have my vertical filter tube appear to be installed cockeyed, but its not. and a bow front sort of magnifies a bit more than a flat pane does........makes no difference if its acrylic or glass.
I have both, prefer glass and after this past weekend with making the wife a new custon acrylic container for her hermit crabs (Land types) and knowing how carefull she is in what she does, the inside is full of tiny fine scratches just from smoothing the sand down etc.......granted those fine hair scratches would probably not be visible if water was in the tank as water does help hide some scratches, it scratches very easy just the same.........as will glass, but not quite as easy....And yes scratches can be removed from glass but not normally by a home type....I had a large scratch removed from a 90 gal FW tank after I almost lost a large rock I was placeing in the tank, managed to grab it but cold not hold it but managed to wedge and allow it to slide to the bottom instead of busting though the bottom.....I carried the tank to a windshield repair place and had them fill the scratch with the material they use to fix chips and such in windshieds, and its held up perfectly for over 6 years now....OH,m and they did not charge me for the fix, as they were curious as to if it would work and hold up, as it maay mean other walk in business if it worked.......and glass is also able to be worked with various grades of abrasive compounds to reduce or remove scrathces as well, but if not done properly you still run the rish of making a distortion thats worse than the scratch is.
