7 DIY Aquarium Background Ideas (3D Foam & Black)

diy aquarium background

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Aquarium owners are always looking for new and innovative ways to make their tanks look better. If you’re bored of the traditional black or blue background, why not try something a little different? There are a lot of DIY aquarium background ideas out there, and most of them are easy to do.

Whether you want a way to add some personality to your tank or something more realistic, here are 7 DIY aquarium background ideas that will spruce up your tank without breaking the bank.

So start planning your amazing new aquarium background today!

DIY 3D Aquarium Background

A popular trend in recent years has been to create DIY 3D backgrounds. These backgrounds can add visual interest and depth to an aquarium, and they can also provide a place for fish to hide and explore. While many fishkeepers choose to purchase pre-made backgrounds, it is also possible to create your own.

With some pink foam, paint, and a little bit of creativity, you can design and install a custom background that will transform your fish tank into a one-of-a-kind underwater world.

Despite their cheaper cost, these projects are very time-consuming and messy. If you’re not careful, you may end up with a mess of bubbles and foam floating around in your tank. But if you take your time and plan everything out beforehand, you’ll be able to create a beautiful and unique aquarium that will be the envy of all your friends.

DIY 3D Aquarium Background with Pink Foam and Silicone

I was very impressed by this idea when I found it seven years ago, and I knew I had to try it out for myself. This is a great way to add some dimension and visual interest to my cichlid aquarium, and it looks really cool when completed.

This project is a bit more involved than others on this list, but it’s definitely doable if you’re patient and have some basic skills. You should choose the right foam board. Some brands have a plastic cover on them, which are obviously not what you want.

It’s very important to use aquarium-safe silicone, meaning it’s 100% silicone with any mold or mildew inhibitors. GE GE012A Silicone is a good option.

Find out how to make it here!

Make 3D Aquarium Background Using Foam‑iT!® 5

Compared with carving pieces of pink foam to get your desired shelves and rocks, this is an easy way to create custom foam rock walls that will look great in any aquarium. It’s also much less messy as it doesn’t require any cement.

All you need is some Foam‑iT!® 5 Rigid Foam, an expanding urethane foam that comes in liquid form. Once it expands and cures, it’s very strong and lightweight, making it perfect for aquarium use.

The hardest part of this project is deciding on the designs of the rock formations and shelves. Once you have that figured out, the rest is easy. Additionally, it costs more to make an entire background using this method.

Foam-iT! 5 - Rigid Polyurethane Foam - Pint Unit
  • Two component castable rigid urethane foam
  • Expands 10 times its volume
  • Cures tack-free in 6 minutes
  • 5 pound density - great for propmaking, gap filling and more
  • Easy to measure and mix - 1:1 mix ratio by volume

Find out how to make it here!

DIY 3D Aquarium Background Submerged Tree and Rocks

The 55-gallon do-it-yourself aquarium background is made of three layers of polystyrene sheet foam that have been glued together. The first two layers were carved into the desired submerged tree and rocks, and the last layer was glued on top. This provides a realistic 3D effect that will look great in any aquarium. Plus, the richer brown and charcoal grey colors will really make your fish and plants pop.

Find out how to make it here!

Created Faux Rock Wall DIY Aquarium Background

DIY Aquarium Backgrounds on YouTube are a dime a dozen. This tutorial created by Kevin is definitely one of the best ones. Kevin uses the same styrofoam that is easy to find and cheap. One of the best things about this tutorial is that Kevin shows you how to carve ledges and overhangs, which is often overlooked in other tutorials. He also shares some helpful tips and ideas.

The final product looks amazing and very professional. I would recommend this tutorial to anyone looking for a detailed, step-by-step guide on making their own aquarium background.

DIY 3D Background with Sand Waterfall

Here is another brilliant video tutorial on how to make a DIY 3D aquarium background with silica sand waterfall. This time, the tutorial is brought to you by Craig.

This is a very detailed and easy to follow video, which is great for beginners. Craig does a great job of explaining each step clearly. Moreover, she shares some mistakes and fixes to help you create a beautiful aquarium background without spending much money.

The final product looks fantastic and is sure to impress your friends and family.

DIY Black Aquarium Background

For those who want something easy and elegant, a black aquarium background is a way to go. Black is always in style. Not only does it provide a neutral background that won’t clash with your fish or plants, but it also camouflages all your aquarium equipment as well as algae and mineral deposits.

Two practical methods are to either buy a large piece of adhesive black poster board or vinyl and glue or tape it to the back of the aquarium or to paint the back of the aquarium.

DIY Black Aquarium Background with Background Adhesive

The easiest way to make a DIY black aquarium background is to buy a piece of aquarium background or vinyl and adhesive it to the back of the aquarium. They can be trimmed to desired shape and size easily.

Here is a good one.

SPORN Aquarium Background, Static Cling, Classic...
  • HIGH DEFINITION IMAGES: With its vibrant colors and detailed HD images, it is sure to create a lifelike...
  • FITS MOST AQUARIUM: It can be adjusted to fit most aquarium sizes. You can quickly cut the sheet...
  • EASY APPLICATION: The static cling design enables hassle-free application. Just remove it from the...
  • RESIDUE FREE REMOVAL: The cling adheres directly to the aquarium and does not damage the tank upon...
  • CUSTOMER SATISFACTION: Made from premium quality material has gone through stringent quality tests. Our...

Painting The Back Of Your Aquarium Black

Although painting sounds like a lot more work, it actually isn’t. It’s very easy to do, and the results are great. Plus, you can always repaint it if you want to change the look of your decor down the road.

There are many reasons why you should paint your aquarium black instead of using a piece of adhesive aquarium background.

  • Paper will fade while the paint is permanent.
  • Adhesives fall off or bubble over time
  • Removing paint from glass is not too difficult.
  • You won’t be able to replace the background easily since your tank is going to be heavy.

Three things you must remember when painting your aquarium black:

  • Never paint the inside of your aquarium, only the back, as you don’t want to poison your fish.
  • Never use soap of any kind to clean the inside of your tank.
  • Depending on the materials of your aquarium rim/frame, sometimes, the inside edge of the rim can’t be painted, so you can see it from the inside of your tank. Generally, it will be covered the lid/hood and lighting unit, but it’s something to keep in mind.


If you’re looking for a unique and eye-catching backdrop for your aquarium, why not try making your own DIY aquarium background? There are endless possibilities when it comes to creating an original look for your fish tank, and with a little bit of creativity, you can come up with something truly special.

Whether you’re a crafting novice or an experienced DIY-er, we hope you give one of these DIY aquarium background ideas a try. And be sure to share pictures of your finished product with us on social media – we can’t wait to see them.

So get started on your project today and show off your handiwork to your friends and family!

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Jeff Colt

Jeff Colt

Hello, I'm Jeff- an aquarium enthusiast with over 25 years of experience caring for a wide array of tropical fish, including koi, goldfish bettas, cichlids and more! For me: Aquariums are like jello - there's always room for more!

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