Review on Efficient Magnetic Aquarium Glass Cleaner & Brush: Saim Fish Tank Cleaning Tool by Michael Woods

Not the strongest, but does its job well. I have a 6 foot tank with 1/2 in glass. The magnet is just strong enough to handle 1/2 glass. If the glass had been thicker I doubt it would have held up. I have this to keep on one side of my jar so I don't have to constantly move it from side to side. As I said, the magnet is not very strong, but it is enough for 1/2 in glass. I like it because it cleans well and I don't have to exert that much to move it. My other magnet lets me work out because it's too strong. I only gave 4 stars because the scraper is a little flimsy, but other than that it's perfect for 1/2" (again, no more than 1/2"). Although I may have to take it down a few times, it does remove the coralline algae. the glass.update: 4-10-18 Less than 4 months later the blade rusted. This is after I wipe the blade down with a rag. It's pretty rusty