Here are 11 of the most creative fish tank decor ideas that highlight some of the best methods for building unique aquarium designs.
I spent the whole day searching the internet and watching videos to compile this list to help inspire your next tank and give you some insight into the processes and costs involved for different styles.
It’s easy to get overwhelmed with ideas, but just remember any fish tank decoration style is just different combinations of a few key elements organized in different ways:
- Substrate / gravel base
- Plants (living or plastic)
- Objects or ornaments (like caves, rocks, logs, shipwrecks or statues)
- Background
- Lighting / color scheme
Here are the decor ideas
Betta Bridge To Nowhere
Classic Planted Sunken Log
Zen Calming Aquarium
Mini Barrier Reef Tank
Ancient Shipwreck Discovered
Star Wars Themed Fish Tanks
Hidden Cave
Lost City Of Atlantis
Super Mario Lego Build
SpongeBob Square Pants Undersea Adventure
Fish Tank Backgrounds
Keep in mind that any of these designs can be adjusted to fit whatever tank size you have, they are meant to be inspiration.
Betta Bridge To Nowhere
This aquarium decoration idea from Mr. Decor really shows how creative you can be with making some choices with your substrate. This design features a bridge insert, but the real stand out is the layering and use of Flourite Black Clay Gravel aquatic substrate to create hills on the side and then a separate midsize gravel to create the riverbed effect down the center. The design is then finished off with numerous live plants to create a lush fish tank atmosphere for a betta fish.
When working with sand or gravel it’s a great tip to use a clean and dry paint brush to evenly spread it around to create gentle hills. After you landscape your base, remember to gently pour the water in using your hand to prevent it from shifting or washing away your gravel.
About The Design
- This example design is built around a 5-gallon tank, but could easily be scaled for other sizes.
- The estimated cost for this tank design is about $150-$200 (excluding tank, filters, thermometers, etc).
- 15 LBS of black flourite costs about $30, the bridge will cost between $20 – $40 depending on the style you choose, and then the live plants will cost between $100 – $150 depending on how many and which ones you choose. This is an area you could save some costs with fewer plants or using artificial for easier keeping.
Classic Planted Sunken Log
This tank design features a sunken log design on top of a simple gravel base to give a central eye focusing point before layering in numerous live plants. The design feature that makes this unique is the use of many different types of plants that all grow to very different heights.
Towards the front of the tank and the edges are places the shortest plants while closer to the center they get taller and the back has grasses that go all the way to the surfuce. This is unique technique that helps create a sense of depth in the tank and eye flow towards the center.
About The Design
- This example design is built in a 17-gallon tank, but again can be scaled easily to a smaller or larger design.
- This design costs between $150 – $300 to build. The substrate costs is around $20-$30, the wood is about $20-$40 (or free!) and the plants will range from $100 – $200 depending on how many and which ones you choose.
Zen Calming Aquarium

We’ve lately seen this popular theme of a buddha statue as the centerpiece in a fish tank. It can definitely give off a calming vibe, particularly when paired with some plants to give it a natural of “lost buddha statue” feeling. Like you discovered something unique in the jungle.
About This Design
- This design is one of the lower-cost options we have here. Buddha statues run from about $10-$30 each, the gravel base will cost about $20, and some live bamboo shoots that can be planted cost about $20-$30.
Mini Barrier Reef Tank

If you are up for a challenge and are going for a saltwater tank, you can grow real coral and design a tank just like you might see snorkeling or scuba diving. These tank designs tend to have sand bottoms as you would find in nature, and then coral skeletons or rocks in the tank to grow your coral. If you are going freshwater or want an easier-to-maintain tank, there are many artificial coral choices.
About This Design
- This tank features artificial coral with very bright colors. The designs shown here from Instant Reef are beautiful but on the pricier side ranging from $25 to $500 depending on the sizes and pieces you want.
Ancient Shipwreck Discovered


Getting into the world of sunken ships and shipwrecks has many options, but they all start with the shipwreck you choose. You can go with a wooden-style pirate ship, sunken WWII battleship or even the titanic. Most designs center around the wreck on a simple base, and layer in some plants to create depth or the image of a long-lost wreck, just peeking out from its final resting place.
About This Design
- You can find plenty of wreck designs ranging from about $20-$50.
- If you want to layer in some plants or fancier substrate, expect to pay another $50 – $150 for additional materials.
Star Wars Themed Fish Tanks


Nothing says you are a true Star Wars fan like letting your betta fish swim around the Death Star. And luckily, there are plenty of battle walker, Millenium Falcon, and X-wing fighter models to put in your tank. We have 2 examples above that have different styles. The first has a simple battle walker but uses a great background image with the death star. The second option is more of a lost-in-time fighter that’s slowly getting lost under its plants.
About This Design
- The models typically cost about $10-$30
Hidden Cave

Tanks with caves are a great option for giving your fish a place to hide out and make their own private space. They can be fun for you as well to watch and play a little hide and seek. There are 2 basic ways to create a fish tank cave. First, you can purchase premade cave features that look like rocks, or buildings. Or you can get your own rocks and stack them to make your own designs. Just be careful to ensure they won’t topple over by stacking carefully or gluing them together.
Lost City Of Atlantis


There is something about the lost city or crumbling roman ruins in a fish tank that is fun and takes us back in time. And lets your imagination roam freely across the sunken streets. There are plenty of options for building or city ruins for your aquarium that range from a few simple columns all the way to mini colosseums.
We’ve got 2 examples here that again display things either front and center with the architecture as the main viewing point, or the more overgrown and hidden with just the hint of the stones peeking out from the plants.
The concept on the left with the statue is from Big Al’s themed tanks and he actually shows a few different plant variations to give it different color themes.
About This Design
- Ruin columns or Roman temples range from about $15 to $45
Super Mario Lego Build

This design is creative in a 2 birds 1 stone kind of way. If you are a Mario fan you’ll recognize these images immediately and to make it all that much more interesting, these were built with legos.
About This Build
- Are LEGOs safe to put in a fish tank? Yes, LEGOs are safe in your fish tank and won’t hurt your fish with any chemicals. This is because LEGO blocks are made from ABS plastic which is a stable material and doesn’t leach hazardous chemicals that could harm or kill your fish.
SpongeBob Square Pants Undersea Adventure

There is no shortage of SpongeBob inspired fish tank ideas, and they are all incredibly fun. There are plenty of SpongeBob characters and building options including his pineapple under the sea! These designs usually feature a simple sand bottom and let the characters stand out and shine on their own. Some variations feature more color with purple and blue rocks on the tank bottom.
Fish Tank Backgrounds For Adding Depth


Probably one of the simplest and fastest decorations you can add to your fish tank is a background image. The ideas are almost unlimited. You can do something traditional like an underwater theme or a beach theme. Or, like we showed above – something completely unexpected like the death star! You can buy fish tank specific images online or at a pet store, of find other images and have them printed professionally in the size you need.
Thanks for checking out these aquarium design ideas and remember that you can get started with as little as $20-$30 and build out very detailed concepts for $200-$300.
Other Considerations
When you are coming up with ideas, make sure to keep a few basic safety items in mind for your fish tank.
- First, beware of any items with sharp edges or corners. You don’t want your fish to get cut or scraped when trying to squeeze through caves or wrecks.
- Keep your tank dimensions in mind so that you have both plenty of space for your great decor, but your fish still have plenty of space to swim, hide and maintain their normal lifestyle.
- Most commercial fish tank items specifically designed for this use are 100% safe to put in your tanks, but we’d still recommend carefully washing them after removing them from the package. If you are using DIY fish tank decorations, make sure they are properly cleaned or quarantined before using them. It’s also good to double check they are nature or won’t leak any chemicals that could harm your fish.