I never wanted an acrylic tank but the price and convenience of getting one I cant pass up. I know the differences between acrylic and glass. So what I am wondering is , are they really that easy to scratch? I mean if I set a rock next to the acrylic is it gonna leave a mark? How easy is it to buff out a scratch? Can you buff a scratch with water in it. What tools and cleaning method do you use to keep the acrylic clean?