10 Inspiring Aquarium LEGO MOCs: Instructions, Tips and Ideas

10 Inspiring LEGO Aquarium MOCs (Ideas, Tips & Hand-Picked Models)

Aquarium builds are one of the most satisfying themes in the LEGO world: they’re colorful, compact, and full of life. A great aquarium MOC lets you play with organic shapes (corals and seaweed), transparent elements (tanks and bubbles), motion (swimming fish, rising “air” streams), and storytelling (keepers, visitors, and exhibits). Whether you’re aiming for a small desktop fish tank or a full modular public aquarium, the key is balancing clarity and detail—enough visual interest to feel alive without overcrowding the scene. Trans-clear panels and curved windscreens can form elegant tanks; 1×1 round plates, flower studs, horns, and bars become coral, anemones, and sponges; and simple clip-bar assemblies create schools of micro-fish perched at dynamic angles.

Think about flow when you design: where will visitors walk, where are feeding stations, and how does filtration “look”? You can suggest pumps with dark-bluish gray cylinders and flexible hoses, build viewing tunnels using arch bricks and SNOT windows, or hide lighting (if you add LEDs) behind trans-light blue tiles to give the exhibits a gentle glow. Texture sells the seabed—mix tan, dark tan, sand green, and nougat plates, then layer with round tiles and curved slopes for dunes and rocky stacks. Finally, add a few humorous touches: a mischievous crab near a dropped hotdog, a turtle peeking through kelp, or a keeper mid-presentation. These vignettes make your aquarium feel like a place, not just a box of water.

Tips for Building Aquarium MOCs

• Tank clarity: Use trans-clear panels/curved windscreens; cap vertical seams with tiles or corner pillars to hide studs.

• Water effect: Stack trans-light blue tiles over white plates; sprinkle a few trans-clear 1×1 rounds for “bubbles.”

• Corals & plants: Mix bars, clips, horns, flower studs, foliage, and whips; vary heights and colors for a reef look.

• Rockwork: Combine wedge plates + curved slopes; keep irregular edges and overhangs for natural silhouettes.

• Fish & creatures: Microbuilds with quarter tiles, cheese slopes, and tooth plates; mount on clear bars for “swim.”

• Storytelling: Add tickets, signage, feeding tools, benches, gift shop or snack stand to bring the scene alive.

• Structure first: Build a sturdy base (plate/small brick sandwich) before placing tanks and delicate reef details.

• Modularity: Design floors/tanks as removable modules for easy transport and upgrades.

Ideas for Types of Aquarium MOCs

• Desktop Fish Tank for a shelf or office.

• Public Aquarium (Modular) with lobby, multiple exhibits, and a rooftop feature.

• Character Tank (e.g., clownfish & pals), perfect for kids’ rooms.

• Jellyfish Cylinder with vertical “tentacles.”

• Shark Tunnel using arches/SNOT windows.

• Touch Pool with starfish/crabs and low rail.

• Reef Research Lab mixing science gear with tanks.

• Harbor Rescue Exhibit featuring turtles/rehab areas.

• Mechanical/Motion Tank (cams to “swim” fish).

• Microscale Coral Reef vignette.

Featured Aquarium MOCs

City Aquarium

Designer: Legofan21.
Get the instructions: Model – City Aquarium | Designer – Legofan21

Aquarium

Designer: gabizon. 
Get the instructions: Model – Aquarium | Designer – gabizon

Aquarium Modular (Alternate build of 3×31118 Surfer Beach House)

Designer: re-bricked. 
Get the instructions: Model – Aquarium Modular (Alt of 3×31118) | Designer – re-bricked

Dory and Nemo’s Aquarium

Designer: IScreamClone. 
Get the instructions: Model – Dory and Nemo’s Aquarium | Designer – IScreamClone

Sea Aquarium

Designer: Jildos_legoplanet. 
Get the instructions: Model – Sea Aquarium | Designer – Jildos_legoplanet

Visit to the Oceanographic Museum

Designer: Thierry. 
Get the instructions: Model – Visit to the Oceanographic Museum | Designer – Thierry

Aquarium

Designer: BrickHappens. 
Get the instructions: Model – Aquarium | Designer – BrickHappens

Electric Aquariums

Designer: kermith72. 
Get the instructions: Model – Electric Aquariums | Designer – kermith72

Aquarium

Designer: felix.rebricks.
Get the instructions: Model – Aquarium | Designer – felix.rebricks

Fish Tank Aquarium

Designer: brotherdevin. 
Get the instructions: Model – Fish Tank Aquarium | Designer – brotherdevin