Glass or Plexi? Deep scratches are tough....by the time you've polished them out, you've now distorted the glass/plexi. Slight surface scratches can be buffer out....and if you want to pay, it will cost you. A local friend had his plexi tank buffer out and it cost over a thousand bucks, and he had to bring it down to Delaware....and back. Try doing it yourself.....google it and you'll find instructions.