I'm in a bit of disbelief. I have a very deep freshwater tank and for years have scrubbed the bloody thing with manual scrapers until my hands and arms cramped. I've tried other magnetic scrapers but none worked well enough. This losing battle led me to give up mostly and only scrub clean for viewing, and that only occasionally. Fed up I searched Amazon based on customer reviews and found this. While pricey, I thought I'd try it in case it actually worked. And...IT DOES! I was giggling and hollering as I easily cleaned parts of my tank that has haunted me for years. It's not perfect, as sometimes you have to try different angles, but it's simple and effective. LOVE IT!