Let me just say that this thing works perfectly.
Let me just say that this thing works perfectly. I'm usually very worried about scratching the glass with sand with other scrappers, but this one eliminates that fear. Not only that, but I only need to do 2-3 scraps to eliminate that pesky coraline algae. Otherwise it takes 1 pass to remove all other kinds of algae and makes for keep the glass clean a breeze.