This cleaner is perfect for my nano tank, the Fluval Betta 6 Gallon. It really cleans off the algae, but the handle which rubs the outside of the tank leaves a little adhesive residue on the glass. It’s probably because it’s brand new, but you can easily wrap a thin cloth over the handle to prevent any contact with the glass, if you want because the magnet is quite strong!
Great product, I highly recommend it!