Aquarium Fish tank Glass Algae Scraper Blade Cleaner - Razor Coralline Calcified rust-resistant blades are ideal for removing coralline algae and calcified deposits in glass aquariums. blade x6 Not suitable for acrylic tanks Product name Fish tank glass Algae scraper Description rust-resistant blades are ideal for removing coralline algae and calcified deposits in glass aquariums. blade x6 Not suitable for acrylic tanks Measures approximately: lenth14.4cm (5.6") wide10cm (3.93")