Magnetic algae scrapers are excellent tools for quickly and conveniently cleaning the glass and acrylic walls of your aquarium. Their versatile pads remove all types of growth, including coralline algae, diatom blooms, and pretty much anything else that manages to stick to the normally slick surfaces. That said, a magnetic algae scraper can also quickly devastate the aesthetic appeal of the aquarium. Just as it removes algae, a scraper can gouge out a nice, deep scratch right across the front of the display. Things like grains of sand and small snails can get trapped between the scraper and the walls of the aquarium, causing significant scratches that just ruin a good looking reef or fish only system. So, be careful with these scrapers and inspect them regularly. You might even want to remove them after each use just as an extra measure.