Decorations are one of the most important parts of any aquarium setup. You need decorations to give fish objects to interact with and of course, keep your tank looking appealing!
If you’re in a creative rut over how to aquascape your latest tank here are 20 awesome aquarium decoration ideas to consider!
Driftwood
From Choya Cactus to Indonesian Mangrove roots, there’s a driftwood type for everyone’s taste. Driftwood is for hobbyists looking for a strong natural aesthetic. The twisting branches give fish a place to hide, rest, and breed. Some, such as the Bristlenose Pleco, even eat waterlogged driftwood!
You can use either large showpieces or smaller branches in nearly any setup. Just keep in mind that driftwood tends to alter water chemistry. The plant tannins tend to shift the pH towards acidity and keep it there, acting as a buffering agent.
These same tannins can also give the aquarium a tea-stained appearance, depending on the type and size of your driftwood piece. Fortunately this does fade with time.
Indian Almond Leaves
Indian Almond Leaves are used in blackwater biotopes and aquascapes to help buffer the pH towards acidity, much like driftwood. The leaves also have potent antibacterial and antifungal properties that bolster fish immunity and even encourage breeding in soft water species like Discus and Tetras.
Scattered about the bottom they create the appearance of a forest stream or natural lake. Indian Almond Leaves also last a lot longer than most leaves and are guaranteed fish-safe, unlike the random leaves you might gather on your own.
Clay Pots
If caves are hard to come by, clay pots are the next best thing. They can be used either whole or broken into sections for smaller aquariums.
Clay pots make instant caves for territorial bottom dwellers like Cichlids, Catfish, and Sharks. Shy, nocturnal species like Knifefish also appreciate having a place to retreat to during the day. Many fish that care for their eggs or young also use clay pots as a place to spawn.
If you do end up breaking your pot to use a section make sure you sand down the sharp edges. And if reusing a clay pot from your garden I recommend scrubbing it thoroughly and letting it soak for a few days to remove any fertilizer remnants.
Plastic Plants
Not everyone wants to bother with full spectrum lighting, carbon dioxide, and fertilizers. Since live plants need quite a bit of attention plastic plants are a great way to achieve the same look.
Many closely replicate the appearance of aquatic plants, letting you choose replicas of popular species like Hornwort and Elodea. You can even plant a background of plastic Eelgrass (Vallisneria) with no chance of it dying on you.
While you don’t get the oxygenating and nutrient consuming benefits of live plants plastic versions are inexpensive and a great way to quickly achieve a finished aquascape.
Live Aquatic Plants
Planted aquascapes are one of my personal favorite setups. Live aquarium plants are sometimes a challenge but provide benefits like oxygen and the consumption of nitrates to fish.
The variety available is nearly endless as well, from creeping foreground plants like Dwarf Baby Tears to towering background species like Amazon Sword Plants.
Fortunately, there are plants for every skill level. If you’re not looking to get into carbon dioxide additions, enhanced lighting, and enriched substrates take a look at my Easy Low Light Aquarium Plants for Beginners guide.
Terrestrial Plants
Many terrestrial plants can grow out of an aquarium. Spider Lilies are famous for being paired with Bettas in bowls as they are not only hardy but grow well with indoor ambient light. They can just as easily be used with a larger tank.
Sweet potatoes are another species that creates massive root networks for fish to explore. Just remember that like most plants, they need bright lighting for their leaves and won’t thrive in ambient light. Overhead full spectrum lighting is essential but rewarding if you decide to take on this project.
Plastic Sculptures
If you’re looking for a specialty aquarium decoration idea you can’t do much better than plastic sculptures. Every pet store carries dozens to hundreds of types ranging from smiling Buddhas to massive castle ornaments.
Plastic sculptures are non-toxic, easy to clean, and help solidify a given theme, such as “East Asian” or “Pirate Cove.” Even planted aquascapers sometimes include a small hut or cave when rocks don’t quite do the job.
The rough surfaces of these sculptures also provide anchoring points for epiphyte plants like Java Moss and algae. Eventually your Buddha will gain a green bushy beard for Plecos and Snails to tidy on occasion!
Rocks
Natural rocks are a great way to add hardscape to both fresh and saltwater aquariums. Seiryu Stone is especially popular for freshwater tanks due to its striking blue and white striped coloring.
Both rough and polished rock can be used to create effects. Smooth stones often create the feel of a stream or river environment while rough ones work better for a lake scene.
The only downside to using rocks is that many affect the chemistry of your aquarium water by leaching carbonates and other hardness-raising minerals. It’s best to stick with igneous and metamorphic rocks as they are less likely to affect chemistry.
Floating Rocks
Fans of the movie Avatar should consider this aquarium decoration idea! Floating rocks take a little more work to set up but are undoubtedly unique!
Instead of standard rocks you’ll need chunks of pumice, an air-filled volcanic stone that’s lighter than water by volume. Look closely at the video; you’ll see transparent fishing lines attached to both the stones and the bottom of the aquarium.
Each rock also has a healthy colony of green aquatic moss. Other possible plants to use in this setup include African Water Fern and Anubias!
Live Rock
Live rock is a staple of the saltwater aquarium hobby. These coral blocks are usually coated in sessile organisms, including Corals, Christmas Tree worms, sponges, and macroalgae. Hitchhikers like Snails and Crabs may also find a way into your aquarium if you’re lucky!
Live rock also contains micropores where beneficial bacteria and scavenging invertebrates live. These unseen cleanup crewmembers aid in the biological cycles of your ecosystem.
For larger aquariums I do recommend using silicone to fix live rock in place as blocks can shift and potentially crack glass.
Corals
As the aquatic plant analog of the saltwater world Corals are some of the finest aquarium decoration ideas possible. They come in two main varieties: stony, with hard aragonite skeletons and soft.
Both kinds rely on intense lighting to feed their symbiotic algae and impeccable water quality to survive. Many aquarists use protein skimmers to prevent organic matter from breaking down into nitrates which corals are especially sensitive to.
Many corals fluoresce under blue and black lighting as well, adding to their mystique. Anemones are relatives without stony skeletons that tend to be more mobile but are also iconic reef invertebrates!
Specialty Substrates
Gravel is an aquarium decoration some hobbyists don’t put much thought into. However there are tons of gravel choices that go beyond pink or blue!
Mixed substrates with a variety of particle sizes from sand up to pebbles help recreate the look of a river bed. And fine sand is perfect if you’re keeping fish that like to burrow like Kuhli Loaches!
Planted aquarium substrates not only look great but also provide places for essential nutrients to collect and be taken up by aquatic plants. For saltwater aquariums white coral-based live sand provides a home for beneficial bacteria and jump-starts the cycling process.
Seashells
Seashells can find a ready place in both salt and freshwater aquariums. Conch shells are especially popular since they can double as caves for fish small enough to fit within.
Seashells also provide new homes for hermit crabs once they outgrow their old shells and hard surfaces for coralline algae and freshwater mosses to attach to.
Being made mostly of calcium carbonate, Seashells will eventually dissolve, especially in aquariums with a more acidic pH. However they don’t impact pH and hardness nearly as much as rocks unless your aquarium is smaller.
Plastic & Metal Rubbish
While untraditional rubbish is certainly a sign of the times and can work well for biotope aquariums where realism is key. Soda cans and coins can add a touch of human impact and raise awareness of ocean pollution and other sustainability-oriented issues.
In larger aquariums pieces of broken pottery, dishes, or glass bottles work nicely as accent points. Large pieces of PVC piping from a hardware store can be used to replicate a chemical plant outflow.
Rubbish is versatile and great for storytelling. However I wouldn’t recommend going so far as to add floating plastic bags or soda can rings as they’ll eventually snare your fish or filter.
Bubble Makers
Popular for oxygenation and carbon dioxide diffusion, bubble makers are an aquarium decoration idea that has been around for a long time. A simple curtain of bubbles or a single stream coming from an ornament is a classic choice.
Ring bubblers are a recent alternative that even come with LED lights for an easily installed showpiece. Typically you’d want to be using subdued hood lights such as a black light setup so your LEDs aren’t overpowered.
LED Lighting
Aquarium lighting comes in several types but LED lights are by far the most efficient in terms of power consumption to output. While not as inexpensive as incandescent or fluorescent hoods they compare very favorably to the powerful but expensive actinic and halide setups used for corals.
LED aquarium lights create a nice bright white light that brings out colors in fish and plants. They are often programmable, include a timer, and allow you to select specific shades of bulbs for effects like “Sunrise” or “Twilight.”
Many also provide an excellent PAR (photosynthetically active radiation) spectrum to grow aquarium plants with!
Black Lights
Sometimes people need something a bit more exotic than typical aquarium lights. Speciality bulbs and hoods for black light setups exist that provide a subdued purple-hued illumination. When using black lights stick to black gravel, which often comes with flecks of green and red that glow under UV light.
If you’re a fan of Glofish or fluorescent corals, black lights cause their specialized pigments to intensely glow! Under regular lighting their colors remain vibrant but it takes UV to bring out their full potential.
Exterior Backgrounds
If the wall of the room is too distracting for your aquarium consider using a plastic background. Most pet stores carry them, replicating environmental scenes like aquatic meadows or simply solid color backgrounds.
These background decorations also help control incoming light. For example, a nearby window may allow too much sunlight to enter, spurring the growth of algae carpets. Too much ambient light also causes fish to wash out their colors in an attempt to blend better with their environment.
Spray Foam Backgrounds
One of the most customizable aquarium decoration ideas available is using spray foam to create your own background. Typically spray foam is used in Paludarium setups but it’s also aquarium-safe so long as you give it a few days to cure.
Spray foam backgrounds are truly works of art once you’ve carefully planned out how to put one together. A coating of black epoxy or colored silicone hides the unnatural orange appearance of the foam. The outer coating allows you to add bits of debris, sand, or pebbles before it dries to create the appearance of a submerged tree or rock wall!
Powerheads
Powerheads are very underappreciated aquarium decorations. They create a current ranging from gentle to swift, which affects how fish and plants interact with the environment. Thanks to clever powerheads, plants visibly bow and fish swim in a single direction against the flow.
Powerheads also provide extra oxygenation to sessile invertebrates and places to forage for current loving species like filter feeders.
