Best glass scraper product?

[Reef Pilot]

Can SS blades be used for acrylic tanks? I have been using the plastic Kent scrapers, and having a real hard time keeping the coraline off mine, especially at the bottom near the sand line. The plastic is supposed to be acrylic safe, but with all my vigorous scraping, bits of sand and coraline sometimes get caught in my scraper, and still make scratches.

My new tank downstairs is all glass, and much easier to clean.