These magnets work well for cleaning algae and diatom buildup off of glass. If there is a large problem, you might be better off using a softer sponge and wiping it manually (Aq Co-op has a really great algae scrubber for this). However, for small touch ups it is perfect.
I would recommend this especially for larger tanks with hard to reach areas. It scrubs the glass without disturbing the inhabitants as much.
A very helpful little tool indeed. Absolutely love it, has made maintenance so much easier. Will be getting more for sure.
It's a great little gem, it's working great so far, no visible scratches ....so fingers crossed
Loving this! It’s great for most of my cleaning needs It does as good of a job as my stick scrubbers without any splashing. Great for quick touchups.
I have a light algae problem that takes about two weeks of buildup before its visible enough on the front glass for it to bother me much. I keep snails to keep it in check overall, and mostly bought this scrubby magnet for if guests are coming over or I just feel like cleaning something.
I have found that I like to use this item in a scrubby motion rather than taking long strokes, it seems more effective. However, anyone using this should be careful nothing gets trapped between it and the glass on either side to avoid scratches. When moving the magnet across the glass the interior half "jogs" a bit which actually increases the scrubby motions, and I think helping to remove algae more quickly.
Had I realized just how large the medium is in relation to my tank I would probably have bought the small, because even though it would take longer the thing is very effective so it wouldn't take that much longer, and it would fit better into the nooks and crannies of my tank (making it easier to avoid plants, etc). That said I like the thing and it performs its one job successfully.