Aquarium Magnet

Best magnet to clean aquarium glass

So you want an easier way to clean your aquarium do you? Well, aquarium magnets could be just the thing for you.  Here we will review products to find the best magnet to clean aquarium glass.  But, not so fast, there are a few things you need to know about the dangers of these magnets before you run out to get one. If you have sand or fine crushed gravel (most saltwater tanks nowadays) then you need to be very careful when using the magnet near the sand line. One small grain of sand caught between the magnet and the glass can leave a nasty scratch. This goes double if you have an acrylic tank since acrylic scratches much easier than glass (although, most scratches can be removed from an acrylic tank. Scratches in glass are there forever.)

So, how do we use a magnet to make cleaning easier, and not scratch our beautiful aquarium? Simple, just use these helpful tips:

  1. Never use the magnet within 2″ of your substrate. Clean down there by hand, or use a long scraper to move the sand out of the way first.
  2. Use a pad on the inside of the magnet and always thoroughly rinse after use. Also remember to inspect the pad before your next use. (I suggest White pads so you can see any foreign matter that gets caught like metal shavings or sand)
  3. Use a piece of felt on the outside of the tank between the magnet and the glass. This will allow you to clean the pad before it makes contact with your tank again, ensuring there are no unwanted particles to scratch your tank.
  4. Never leave the magnet inside your aquarium. There are 2 reasons for this. First, you don’t want kids (or some adults) to come by and use the magnet without following the proper procedure, and second, you don’t want your fish or filters to kick up sand that could get stuck in your magnet pad.



Choosing the right size magnet for your tank

Aquarium magnets come in different strengths and sizes. You can use larger ones for thinner or smaller aquariums, but you may end up paying for more magnet than you need and you run the risk of the magnet being too strong and increasing your chances of scratching the tank. Here is a pretty good rule of thumb based on your tank volume to select the right size magnet:

Smaller tanks, up to 30 gallons

For smaller tanks up to 30 gallons (110 liters) I suggest using the small floating aquarium cleaner from Mag-Float (Glass, Acrylic). Way back when I first started using magnets for cleaning my aquariums I had to tie a string to the magnet with a cork on the end of the string, just in case the inside magnet fell to the bottom. Yes, back in ancient times we had to suffer with magnets that did not float, but now, lucky for you if your magnet hits into a rock and flies away from the glass it will safely float to the top instead of sinking like a rock and picking up all sorts of nasty sand and rocks to scratch your glass.


For medium tanks up to 90 gallons

For medium sized aquariums, up to 90 gallons (340 liters). I suggest the medium sized Mag-Float (Glass, Acrylic)



For larger aquariums up to 150 gallons

For larger aquariums, up to about 150 gallons or 565 liters (sometimes larger depending on the thickness of your glass) you should use the large magnet (Glass, Acrylic)


Aquariums larger than 150 gallons

For the biggest tanks we need the strongest magnets! If you have ever used any of the smaller magnets and accidentally got your fingers caught between them you know that it is very painful. With this magnet or even the large one before this, you should NEVER let them come together without something very thick between them. The magnets are so strong that you will need some serious tools to pry them apart and it is very dangerous. So, just don’t let them go near each-other, store them in different rooms, different states, whatever works as long as you don’t end up with your magnets stuck together. Here you can find them in Glass or Acrylic.


For glass tanks only! Above 90 gallons with stubborn coralline algae (reef tanks)

Anyone with a reef tank knows how hard it can be to get rid of the hard algae spots that start to grow all over the glass. If you are like most reefers you will probably scoff at the idea of using a magnet to clean these spots. However, there is hope! Now we have magnets that can attach a metal scraper blade, easily scraping away those calcified spots and reclaiming our gorgeous view port. Here is the magnet itself: Mag-Float Glass with Scraper, Largeyou can also buy Replacement Scrapers if yours gets bent or dull.


The magnets say glass or acrylic, which one do I pick?

If you are using a white pad in between your magnet and the glass(or acrylic), and a piece of felt on the outside glass, then it really doesn’t matter which magnet you choose. The difference is in the roughness of the inside scraper that comes on the magnet. The glass magnets could be too harsh for your acrylic tank and you will end up scratching your viewing pane. If you use an acrylic magnet on a glass tank you won’t have any problems. If you are unsure whether your tank is glass or acrylic you can just use an acrylic magnet to be safe.