Review on Hygger Aquarium Algae Magnet Cleaner: Powerful Magnetic Cleaning Tool with Scraper and Floating Brush for Fish Glass Tank by Heather Laudun

I'm a 300 pound powerlifter who loves aquariums. These algae cleaners are amazing. Cleaned a 55 gallon aquarium with an algae problem in about 3 minutes without blades. I STRONGLY RECOMMEND being careful not to place the two pieces within 4 or 5 inches of each other outside of the tank. The magnets are so strong that when I accidentally did it, they snapped together with such force that I injured my left pinky finger. Then I had to take them apart with a screwdriver! I could literally win some money betting my powerlifting friends that they can't separate the two sides (without a screwdriver or other tool) once the magnets are connected. With a piece of glass in between, they are perfect. I would recommend sliding the outer magnetic part on the glass towards the inner part to minimize the binding force. When you're done, simply rotate one of the pieces in a circular motion while holding the other to break the seal. Buy them, they are great.