How to Make a Magnetic Aquarium Scrubber




Introduction: How to Make a Magnetic Aquarium Scrubber

About: Hi. I'm Jacob, a high school student interested in science and math. I like to build many different sorts of contraptions and perform experiments on topics that interest me. I hope my project tutorials he...

Most aquarium owners tend to experience algae growth and crud buildup on the aquarium walls. This can block out natural light from entering the aquarium, it can obstruct a person's view into the aquarium and can make the overall appearance of the aquarium less than satisfying.

To solve this, aquarium owners can purchase a magnetic scrubbing tool and can use it to scrub the inside of the aquarium walls. However, I enjoy solving problems myself and wish to build my own rather than purchase one.

Using the same design as the store-bought scrubber, my design is relatively cheap, easy to build and very effective.

Step 1: Parts and Tools

For this tutorial, you will need:

  1. Two bottle caps.
  2. Two magnets (the magnets must be strong enough to sandwich the glass aquarium wall but must not be strong enough to break the glass and cause to much friction when scrubbing).
  3. A microfiber cleaning cloth.

And the tools:

  1. Scissors
  2. Hot glue gun.

The microfiber cleaning cloth can be found at any grocery store for a under $4-5. The magnets can be ordered on amazon for a few dollars too. Home Depot and True Value also carry good magnets but for a about $2-3 more.

Step 2: Build It!

Take everything listed in the previous step.

  1. Then, take the micro fiber cloth and cut two circles out that are about 3 inches in diameter. Place a little bit of hot glue in the center and place the bottle cap, face down, over it.
  2. Glue the magnet to the interior of the cap. Then, glue the folds of the cloth over the rim of the cap and onto the magnet.
  3. Repeat for the other bottle cap.

NOTE: Make sure the magnets are oriented so that they attract each other or the scrubber will not work.

Step 3: Using the Scrubber

Congrats! You built your own scrubber.

To use the scrubber, place on bottle cap on the inside of the wall and the other on the outside. Gently let them attract. Use the outside cap as a handle to scrub.

Make sure you use the scrubber every week or so to prevent crud build-up on it.

Thanks for reading!!



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    29 Discussions

    Yes. I let the scrubber sit in a separate bowl of my fish water for about two weeks. I then tested the water quality to see if it changed. It didn't. Now, it has been about two and a half weeks since it has been sitting in my fish tank and my fish are doing great. No signs my fish are affected by the scrubber. However, I really like your idea of aquarium silicone. I was hesitant to get some due to it's high price and availability. It costs more for a small tube than a magnetic scrubber itself!! I will update my tutorial with that idea.

    Also, I have done some research regarding the safety of hot glue and aquariums and it is not necessary toxic to fish. Some people claim it could be and others claim its not. It really depends on the actual hot glue you are using and the aquarium itself (filter, bacteria, water changes, tank size, etc. can alter results).

    I would recommend that if making this for an aquarium and you are concerned about toxicity, use the silicone.

    Thanks for the comment.

    I just searched and found one result on Amazon for them. I will definitely buy a few packs.

    Thanks for commenting and letting me know these glue sticks existed!

    I just searched and found one result on Amazon for them. I will definitely buy a few packs.

    Thanks for commenting and letting me know these glue sticks existed!

    Silicon may not soak into the fibers ...has anyone tried Wacky glue? I know it is ok for salt tanks..should be fine for freshwater. I am not sure how it will react with microfiber.

    It might be okay for freshwater, but I'm a reef tank guy... I guess I was probably thinking in that context. lol

    I think I saw it at my local Lowe's for less than $10 and it would be enough to make several of these probably.

    The dangerous part of glues is the colvents and any componds they create when they cure. Hot melt glue doesn't have any solvents in it and doesn't create any water soluble compouns when is solidifies. I have used it several times in my Aquarium without any issues.

    Other polyurethain glues desolve the polyurethain with solvents. You need to wait at least a couple of days for solvents to evaporate before puting it in the aquarium.

    Silicone rubbers probably don;t have any solvents in them but when they cure two reactions occure. One creates Acidic acid. The other creates silicone oil. The silicon oil is considered safe. But the Acidic acid could create PH problems if it cures in the aquarium. Allow silicone rubber to fully cure and wash it before putting it in the aquarium.

    They are good for eating the algae. They don't seem to eat everything so I thought a scrubber was a good idea for my tank.

    I put in 3 Nerite snails in my 5 gallon aquarium. within a month they cleared all algae groth off of the walls of the aquarium and cleaned up the gravel. Four good measur ethey also cleaned the outside of my filter and scrubber. They are too big to climb on plants and generally don't. For plants shrimp would probably do a better job.


    Neat idea I adapted it to making our house windows easier to clean on the 2nd & 3 rd floor no more long periods leaning out to clean the outside.

    all done now in the warm & dry & NO ladders required

    Thank you & well done

    1 reply


    When I posted this tutorial, I didn't think of the window cleaning idea. I do think it's a great application for these scrubber as well!

    I really like the fact that you have a naturally planted Aquarium. Live plants in a tank help keep Nitrates and Nitrites and your ammonia level lower as well as providing a more natural pleasing environment for your fish.

    I have made my own magnetic scrubbers and as you say, they are not only cheaper but are better at cleaning than the ones you buy.

    Great Job!!!

    1 reply

    Thank you very much.

    A learned that when I set up my aquarium about a year ago and even though they aren't as colorful, they provide, in my opinion, a more relaxing environment to look at. As you said, it also is much better for the fish as well.

    Gr8 idea. Made a similar one myself using a kitchen scrubber sponge and a stick.

    1 reply

    Thanks a lot.

    The problem with stick and sponge is you can't evenly apply pressure to areas that need scrubbing and it is hard to scrub tight areas. However the stick and sponge is cheaper.

    wow too easy, i got taken for 14$ years ago to clean my tank.