There are ways to do it. Time consuming and difficult. You also have to be careful because if you do get the scratches out you can warp the glass, as in by sanding down the glass you are creating a lens effect. So now your view is distorted slightly were you sanded. Not really worth the effort in my opinion.
I had a 29 biocube and tried polishing out the scratches. Not worth it at all. PITA and the results weren't worth it and actually looked worse IMO. You can consider a tank upgrade at this point
Definitely possible, but relatively difficult. Almost always not worth the effort.
Unless you've had practice and have decent skill at it (which most of us don't), it will likely end up worse than before and you will be begging for the scratch back.
I buffed this Biocube. its worth it. lots of elbow grease but doable. i have some jewelers polish aka Cerium Oxide here for free if you want to try. Get a cotton polish wheel and go to town on it. it wont take out anything you can feel with your thumb nail. small lite scratches only... It took me nearly three hours to finally see results. long term not worth it. Biocubes scratch easy and your work would just be in vein as soon as some sand get lodged in the algae scraper.
BTW.. IDK how you made it worse keith but its not hard to do. its just hard work. your arms will hurt and your back will kill, but the overall affect will improve the scratches.