Aquarium Scratch Removal: A How-To Guide 12

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In the course of owning an aquarium, most likely during a cleaning, a scratch might occur on the aquarium’s glass or acrylic surface.

Depending on how noticeable it is, it might be something you decide to ignore, or something you want to get fixed. Thankfully, most scratches in glass and acrylic are reasonably easy to repair.

Editor’s Note: We wanted to know how the professionals do it, so we asked our friend Jon Wolf for some tips. Jon has been an aquarium consultant for over 15 years with Blue Planet Aquarium.

If you didn’t know, Blue Planet Aquarium is the Midwest’s premier aquariums company specializing in custom design, maintenance, cleaning and installations. To learn more about what they do, visit

Protective Measures

If the scratch is on the inside of the aquarium, you’ll have to take some extra precautions to make sure that you don’t contaminate the aquarium during the buffing process.

First, drain some of the water out of the aquarium, giving yourself several inches under the level of the scratch, so you have some room to work with.

Then, place a sheet of plastic foil on top of the water surface, and use some tape to secure the foil to the four sides of the aquarium. This gives you a surface that will catch all the buffing residue and prevent it from ending up inside the aquarium water.

How To Remove Aquarium Scratches

Glass Aquariums

Aquarium Front Scratch

Glass scratches (source)

To buff out a scratch from glass, first you’ll have to get your hands on a chemical called Cerium Oxide (often used by jewelers). Then, buy a hard rubber disk and a buffing pad extension for a power drill or an oscillation tool.

Mix the cerium oxide with water to create a paste, and put a little bit of the mixture on the buffing pad.

You can now begin to buff out the scratch, but be sure to keep the drill on its lowest setting. Buff until the scratch is removed to your satisfaction, checking the glass periodically to make sure it isn’t getting too hot.

When done with the steps above, carefully wipe down the glass to remove any remainder of cerium oxide and you should be good to go.

Acrylic Aquariums


Massive scratches on acrylic (source)

Acrylic is increasing in popularity as a material for aquariums, because of the many options it provides, such as curved walls, spheres, etc. Acrylic surfaces are easier to scratch than glass, but also easier to repair.

To get scratches out of acrylic you’ll just need some wet/dry sandpaper and a solution called NOVUS(think of it as even finer grit sandpaper, in paste form).

For moderate scratches, it’s best to start with around 400 grit sandpaper (remember, always keep the sandpaper wet) and progress to 800, 1000, and 2000 grit.

After you’re done with the 2000 grit, the surface should feel smooth, but will exhibit some “haze” from the micro-scratches made by the sandpaper.

From there, use some Novus solution on a towel and buff until the acrylic is as transparent as it was originally.

As with glass, you have to keep the acrylic surface from getting too hot (acrylic will actually melt under high temperature). You can do this by keeping a small bowl of water and occasionally wiping down the acrylic surface during the sanding process.

There you have it. Whether your aquarium is made of glass or acrylic, the above steps will help you get rid of pesky scratches and restore your aquarium to its previous splendor!

What's Your Experience?

Have you tried removing scratches from your aquariums before? Was it successful?

We would love to hear your own experience and I’m sure the community would appreciate some tips too. Share it with us in the comments section below.

About Jon Wolf

Jon Wolf has been an aquarium design consultant for over 15 years with Blue Planet Aquarium. Blue Planet Aquarium was born out of one unique belief: that aquariums are beautiful and interesting enough to be more than highlights, and deserve to become integral parts of the places they occupy. For more information about Jon Wolf and Blue Planet Aquarium visit

12 thoughts on “Aquarium Scratch Removal: A How-To Guide

  1. Reply Ross McManus Oct 12,2014 12:44 pm

    Thanks for the information. I recently purchased and set up an acrylic aquarium. Immediately I realized that no matter how careful you are, scratches will be a fact of life. This article is exactly what I was looking for. And while I have a chance, I’d really like to thank you for everything that you have posted, I have learned a great deal. I look forward to all future knowledge you have to share.

  2. Reply Jon Wolf Oct 13,2014 4:36 pm

    My pleasure Ross! One note however, if you are going the route mentioned with covering the surface of the water in plastic, do remember that fish need to breath and to keep a section open, preferably with an aerator, to have a good gas exchange and keep your fish happy during the procedure!

  3. Reply Kinley Feb 22,2015 5:43 pm

    Thank you so much for this great tutorial. I have 3 tanks and just purchased a 4th 125 gallon glass tank that was used. It was a great deal with a beautiful stand. However, there are fine scratches on much the inside from where someone scrubbed too hard at some point. It was difficult to see until I started cleaning the calcium buildup off. I will try this method today before filling the tank. Once again, thanks so much..I am relieved!!

  4. Reply Rick May 21,2015 8:50 pm

    Hi Jon, i have a 125 gallon glass saltwater tank. I have a lot of scratches all over the front glass. I have a very healthy tank. I have lots of fish, Anemones, an eel, lobster, starfish and many other things. Is your instruction above the only way to remove the scratches? I am afraid of messing everything up. Should i just live with the scratches?

    • Reply Yvette Jun 20,2015 8:47 pm

      Rick, I have the same problem. Did you find a way to fix it or are you living with it? i would like to remove the scratches from mine as well but it’s pretty full right now.


  5. Reply Corey Willey Jun 12,2015 7:32 pm

    Hi Jon,

    Just got a 225 that has some scratches in it, going to try Novus and hopefully take care of the problem once and for all.

  6. Reply KoolBreeze Jul 13,2015 7:13 pm

    DOes it work on tempered glass tanks as well? I have a 50 gallon tank that was donated to me and it has a label that say’s all panel are tempered glass. I have no worry about fish because it’s empty and I want to buff and add sealant to the edges before attempting to fill and add water it look’s like it was stored improperly and has superficial scratches and I fear a possible leak due to where it’s scratched Could you tell me what is a safe silicone to use as well thanxs

  7. Reply Jamie Oct 14,2016 7:30 pm

    I used the wrong type of sponge to clean the inside of my acrylic tank and now have massive scratches. Will this work for the inside of the tank? will the chemicals cause any issues for the fish after?

  8. Reply Jon Wolf Nov 7,2016 10:23 pm

    Hi Jamie, as long as it is thoroughly cleaned (meaning no remnants) the chemicals won’t pose a problem. But be sure to clean/rinse thoroughly.
    Best wishes and good luck!

  9. Reply Christian Feb 1,2017 4:43 pm

    How deep a scratch can the cerium oxide safely buff out, just got a glass aquarium that has one scratch on inside, can just feel the scratch with nail,

  10. Reply Cathy Oct 4,2017 10:15 pm

    Does removing a scratch help to improve the integrety/strength of the glass versus leaving the scratch in? Or does it make no difference to the strength, only to the looks?

  11. Reply bob Dec 30,2017 9:06 pm

    Tried it didn’t work tank all hazy not happy

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