The sachems algae Scraper is designed with versatility in mind. With three retractable options: metal, plastic, and soft pad, it is suited for both Glass and acrylic aquariums. It is lightweight and features an ergonomic handle making it comfortable to hold in multiple positions. In addition, it floats for easy retrieval. Finally, its White color makes it easy to see the algae you want to remove and when you've effectively removed it. Additional cartridges, blades and pads are available for replacement. Although this is a great tool for any aquarium owner the blade option should not be used on acrylic tanks as it may scratch them.