We carry algae-cleaning magnets from Flipper, Mag-Float, Algae Free, Tunze, and Two Little Fishies (all listed in the Algae Magnet Cleaner section). When choosing a magnet there are five critical questions.

1. Is your Aquarium Glass or Acrylic?
Magnet cleaners often have a scraper as well as algae pads for the tougher algae. The scraper blades are either designed for glass or acrylic. The Flipper and Algae Free come with both acrylic and glass scrapers.

Acrylic aquariums are softer than glass and because of this, no magnet cleaner that is not labeled acrylic safe should be used on acrylic aquariums. Using a non-acrylic-safe cleaning magnet on an acrylic aquarium will almost certainly lead to bad scratches on the viewing panes. You can use acrylic-only cleaning magnets on glass, but because the acrylic scrubbing pads and blades are softer it will be more difficult to remove algae than if you purchased a glass-only cleaner.

2. How thick are the viewing panes?
Magnetic cleaners are rated not by gallons but by how thick the viewing panes need to be for the cleaner to work optimally. The smallest and least expensive magnets can only work with tanks up to 1/4" thick. The biggest and most expensive magnet we carry is the Mag-Float-1000 Super Mag-Float. This magnet is so strong that it will work with tanks as thick as 2 inches. If the two sides of the magnet come together mortal humans can rarely pull the two sides apart. Even with a vice grip, it's hard to pull the sides apart.

If the viewing panes are too thick then the inside magnet will not be held tightly in place—making it harder to scrub algae and easier for the inside magnet to decouple from the outside portion. If the magnet is too strong then it can be difficult to move the magnet across the viewing panes, and there will be an increased chance of scratching the viewing panels. Measure your aquarium viewing panel thickness and choose accordingly.

3. Are the viewing panes flat or curved?
Some popular aquariums such as the Coralife BioCube aquariums and BiOrb Aquariums have curved panels. Flat magnet cleaners will not be able to clean these panels well. The Two Little Fishies Nano Mag, and Two Little Fishies BettaMag are ideal for rounded aquariums. Keep in mind that these magnets still have flat surfaces. They are the best choices because they are small and will make better contact with the inside surfaces of a rounded aquarium than a large magnet. However, the edges might scratch acrylic. Putting a thin filter material on the inside cleaning surface of the magnet will avoid the scratching.

4. How tough is the algae?
Almost any magnet cleaner can get rid of the common annoying green film algae. However, only a few can get rid of extra hard algaes such as coralline algae. The three strongest cleaners for extra tough algae are the Tunze Care Magnets, Flipper Aquarium Algae Cleaners, and Algae Free Aquarium Magnets.

The best solution for tough algae on glass aquariums is an Algae Free Aquarium Magnet paired with the Algae Free Easy Blade accessory. This blade will cut through the toughest algae, but it will also scratch acrylic and can scrape away the silicon that holds glass aquariums together if the cleaner is pushed against the tank corners. Use with care.

5. Worried about scratching the tank?
Nobody likes a scratched aquarium. The most common way people scratch their aquarium with a glass cleaner is by using the cleaner too close to the sand on the bottom and then getting a grain of sand caught between the inside scrubber and the glass. When cleaning the glass the sand grain scratches against the viewing panes. To avoid this, magnets like the Tunze Care Magnet Cleaners are designed to minimize the amount of surface area touching the glass. The Care Magnets are the best choice if you hate scratches.