Do you have a glass tank with tough algae spots that your algae magnet scraper won’t remove? Get an algae magnet scraper that has a removable metal blade.
Mag-Float has a line of algae magnet scrapers that feature a metal blade that will make short work of tough algae spots. They come in small, medium and large, but I suggest using the large magnet on all size tanks up to ½” thick glass with the exception of nano tanks. In my opinion, the small and medium sized magnet scrapers are too weak.