Algenmagnete 100480 Floating Magnet Aquarium Cleaner, Long

Works well, and tested on spare pane of glass - provided clean and no gravel caught it should not scratch at all even though the bristles on the inner piece are very firm. This is needed to get green algae off glass, and it still needs patience and a circular twist is the most effective on really stubborn spots.

Great item. This has the strongest magnet of any glass cleaner I have used (don't get your fingers in the way!!) and cleans the glass with ease.I hadn't used a cleaner for a while so had some stubborn algae on the glass but this cleaner removed all of it with ease. Highly recommended.

These are a great product. It has a very strong magnet, so they can clean most of the build up off the glass. I don't even bother with the small magnets as they are not strong enough.

Watch out! This is smaller than the measurements in product details. This is long and thin, not the large size it gives in measurements. I did let them know about this but they still have not changed the size measurement details.

Great for cleaning the glass on fish tank.