Hepper is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

4 DIY Aquarium Themes & 11 Ideas To Inspire You To Create Your Own

Lindsey Stanton Profile Picture

By Lindsey Stanton


Your aquarium doesn’t just have to be a home for your fish. It can also serve a purpose beyond the functional by being an object of beauty, either blending with or standing out against other decorations in the home.

Luckily, you don’t have to dig deeper into your pockets to buy beautifully designed fish tanks. With a few tools and accessories, you can create your masterpiece.

Decorating the aquarium can seem overwhelming, with so many options available. But you can simplify things by sticking to a particular theme. Below, we share a few DIY aquarium theme you can make yourself and many ideas you can use to craft a tank of your very own. We’ll also offer tips on how to avoid putting your fish in harm’s way.

Top 4 DIY Aquarium Themes

1. Movie Themes

Some of the most popular aquarium themes are based on movies and cartoons. That should not be surprising since films and cartoons are loved by children and adults alike. With so much to choose from, you can create a unique aquarium theme to honor your favorite heroes.

You have the option of buying set-ups with built-in backgrounds. But you can start from scratch and make your fish tank stand out. You only need a uniquely colored substrate and some plastic toys or models.

You are not restricted to a single movie theme, though. You can incorporate characters from different movies or cartoons. For instance, you can create a Disney Ocean theme by including Finding Nemo décor alongside characters from The Little Mermaid.

2. Zen Theme

You can use your aquarium to reduce stress by creating a Zen Garden inside the fish tank. Designing a calming and relaxing view is easy. You only need sand as the base and a few carefully placed stones and plants.

To spice up the look, you can throw in a few rock caves, ancient architectural ornaments, and a Buddha statue. But take care not to compromise the health and well-being of the fish. So, whatever accessories you include should be made from aquarium-safe materials.

A bubbler can be a great addition to your Zen-themed aquarium. It is relaxing to look at and benefits the fish by helping circulate oxygen in the tank.

3. Haunted Theme

diy dark and eerie fish tank
Image Credit: Instructables

Do you love the spooky? A haunted aquarium theme might be up your alley. There are a lot of décor and set-up options to consider depending on how far you are willing to ride the ‘dark train.’

Pumpkins, skulls, and skeletons can work if you are going for a Halloween vibe. You can add a splash of color to bring the scene to life.

A haunted forest theme is perfect if you’re looking for extreme spookiness.

First, you need a pale moonlight background and a dark substrate to set the dark tone. You can then incorporate thick, bare trees with branches rising to the top of the tank. A few dark rocks can help complete the look.

4. Space Theme

diy space theme aquarium
Image Credit: Aquarium Fish Depot

The sky’s the limit with aquarium theme ideas. So why not shoot for the stars with a space-themed design?

There are a lot of cool things you can add to the tank. But it all starts with choosing the right background.

Ensure you pick a background that fits the dimensions of your tank, then add an assortment of toys and accessories. Examples include artificial plants and flowers, a meteorite, an astronaut, and a space dog.

You can draw from movies or classic cartoon characters if you run out of ideas. For instance, you can recreate your favorite episode of Star Trek with a few clever decorations. Characters like the Aliens from South Park or Marvin the Martian also come to mind.

How to Keep Your Fish From Danger

Decorating your aquarium can be fun and exciting. But it can also be dangerous for your fish if you fail to take certain precautions when adding foreign items into the tank. Therefore, choose what things to include in the aquarium wisely.

Some materials contain chemicals and can introduce dangerous toxins or alter the PH level of the freshwater, endangering the fish. Other items could have sharp or rough edges that could fatally injure the fish.

Ceramics, food-safe plastics, and glass are safe for your aquarium.

However, avoiding ceramics with lead and copper glazing is advisable. One-use plastic items such as painted toys could also contain toxic chemicals. Remember to check the glass for cracks or sharp edges that could injure the fish.

There are things you should never use as decor to avoid harming the fish. For instance, metal will rust over time and release toxic oxides into the water.

Untreated wood can also alter the PH level in the tank. The same goes for shells and coral.

Sand is an excellent decoration. But it would be best to consider buying some from the store since regular sand from the beach may contain chemicals and bacteria.

Also, avoid adding anything degradable unless it’s safe for the fish to consume. A fish will nibble at anything in its environment when foraging for food, whether it’s part of its diet or not.

tropical fish 1 divider

Additional 11 Aquarium Theme Ideas

1. Meandering Paths

Meandering Paths Aquascape
Image Credit: chonlasub woravichan, Shutterstock

If you’re planning on keeping fish that won’t tear up your plants and make a mess of anything you put in the tank (looking at you, goldfish), then this may be a fun option for you. Using sand, rocks, and even small décor, you can create paths in your aquarium, making them look like terrestrial footpaths. The addition of driftwood and plants can really bring this look together by creating the illusion of trees, shrubs, and grasses.

2. Calming Garden

Calming Garden Aquascape Aquarium
Image Credit: BLUR LIFE 1975, Shutterstock

If Zen gardens are your thing, you can create your own kind of relaxing Zen garden in your aquarium. There are many pieces of aquarium décor that will fit in with this look. You can also use a sand substrate with rocks, like you would in a real Zen garden, but be aware the rocks will sink into the sand over time. Bamboo can bring a beautiful touch to this look and it can be kept partially submerged. If the leaves are out of the water, your bamboo should thrive.

3. Bikini Bottom

Spongebob Aquarium
Image Credit: Samuel Koval, Shutterstock

Are you a Spongebob Squarepants fan? Then there’s great news for you because Spongebob-themed aquarium décor is popular and easy to find. You can create your own Bikini Bottom, complete with a Krusty Krab restaurant and even Spongebob himself. You can have fun with this setup, creating your own underwater world.

4. Halloween Town

Halloween Town Aqurium
Image Credit: haireena, Shutterstock

Many people are into the aesthetic of spooky décor, which can be extended into your aquarium. Whether you want a playful spooky aquarium or a spooky spooky aquarium, there are décor and setup options for you. Skulls, skeletons, and pumpkins can bring in the Halloween vibe. There are even aquarium-safe headstones! Dark substrate and plants can bring a sense of organization and completion to your spooky theme.

5. Natural Look

Plank tank green beatiful aquascape
Image Credit: Gengarrr, Shutterstock

Is your idea of an aquarium theme a non-theme? The natural look is probably right up your alley. This allows you the freedom to choose any décor you want, if any. You can use rocks and driftwood to create different natural-looking underwater scenes. Spiderwood is a great option for creating tree-root looks, but when flipped over can also be used to create “trees” with plants and mosses attached to the branches. This theme opens up limitless opportunities for what you can add to your aquarium to make it your own.

6. Princess’s Dream

An image of a colorful fluorescent color aquarium accessory displayed at the shop
Image Credit: Rosli Bakar, Shutterstock

The princess and unicorn theme is very “in”, so décor for this type of theme is very easy to find. There are bright substrate options, pink and purple faux plants, and aquarium ornaments in this theme, making this an easy theme idea. This is a great option for an aquarium in child’s room, but many adults appreciate the child-like fun of this type of theme.

7. Pirate’s Dream

pirate aquarium theme
Image Credit: Oleg Kopyov, Shutterstock

Princesses not your thing? Maybe the classic sunken pirate ship is more up your alley! Pirate-themed aquarium décor is easy to find, from bubbling treasure chests to full-blown ships that double as caves and hides for your fish. A gold substrate can bring together the idea of sunken treasure, or maybe a dark substrate is more your thing. Plants can be used to create realism, especially on and around ships and treasure chests.

8. Fun and Playful

Neon Theme Aquarium
Image Credit: Bk87, Shutterstock

If a playful theme is what you’re looking for but none of the above interest you, that’s okay! You still have tons of options. Substrate is available in just about every color of the rainbow, allowing you to bring in some bright personality. Some plants, like aponogeton, bring a sense of whimsy to your tank. You can create a fun and playful aquarium with or without the addition of ornaments.

9. Organized and Modern

Modern Aquarium In Living Room
Image Credit: Mulevich, Shutterstock

Some people want an aquarium that blends into the background of their house or matches the décor. Creating an aquarium with clean lines, bright lighting, and full plants can create an organized and modern look in your tank. Choose a substrate that helps the tank blend in with your existing environment and work your way out from there. There are thousands of ways you can set your aquarium up to help it blend in in your house.

10. The Centerpiece

Small fish tank aquarium with colourful snails and fish at home on wooden table. Fishbowl with freshwater animals in the room
Image Credit: Ja Crispy, Shutterstock

Maybe you’re looking for the opposite of something that blends in within your home. Making your aquarium an interesting centerpiece in your home can be fun and easy for you to accomplish. You can go in any direction you want with this theme. You can use bright or colorful lighting to draw the eye to your tank, lots of plants or plants that grow out the top of the tank to make a showy display, or flashy fish can all help make your aquarium a centerpiece in your home.

11. Video Game Theme

diy super mario aquarium
Image By: The Mary Sue

You don’t have to limit yourself to movies. You can also design an aquarium theme around your favorite video game.

There are many modern games today with complex storylines and realistic graphics. So, building a game-themed tank is not complicated, provided you have all the suitable materials.

You can pick a classic game from childhood and create a theme around it. Super Mario is a great example. All you need to do is incorporate a few elements of the game that are easily recognizable, say, bricks, cloud faces, or green pipes.

aquarium plant divider

Final Thoughts

Our list is in no way exhaustive. Many aquarium theme ideas exist, but the options above are a good place to start. The accessories are cheap, easy to assemble and require minimal maintenance.

You can pick a theme that naturally blends with the rest of the décor or consider something that stands out. Alternatively, you can combine different ideas to create an aquarium design that best suits or describes your personality.

Feel free to let your creativity shine, provided you create a safe and healthy environment for your fish. Whatever you do, don’t add toxins or interfere with the PH level in the tank. Also, avoid sharp or rough edges.

You might want to check out some of our top-trending posts:

Featured Image Credit: Aman Kumar Verma, Shutterstock

Related Articles

Further Reading

Vet Articles

Latest Vet Answers

The latest veterinarians' answers to questions from our database