We try to be as careful as possible scraping the algae off of our glass, and we wash and dry everything throughly once we are done using them. For basic film algae we use our tunze plastic scraper but for the more stubborn algae we have to bust out the razor bladeI use this in my nano and found
1) the blades are literally razor blades. Super sharp. Be careful
2) the blades are very thin. It does a great job on everyday film. On crusty coralline they can chip or crack
3) wash and dry fully. They rust easily



