Fish tank decorations have evolved far beyond simple rocks and plants. Today, themed 3D print decor is revolutionizing aquarium and terrarium design. Imagine immersing your pets in ancient ruins, pirate adventures or gladiator arenas — my latest themed 3D print design drop makes it possible. Whether you’re a beginner or a seasoned aquascaper, these new designs are as functional as they are eye-catching.
Why Themed 3D Print Decor Makes a Splash in Fish Tank Decorations and Terrarium Hides
A well-designed theme doesn’t just make your tank look better — it enhances the entire experience for both pets and owners. Here’s how:
- Visual Cohesion: A strong theme brings structure and depth to your setup. Instead of random decor pieces, themed 3D print designs unify the tank’s visual language, giving it an intentional, artistic flow. This turns your aquarium or terrarium into a coherent scene straight out of a movie or museum.
- Emotional Connection: Tanks become more than habitats — they become stories. Each print reflects a tale of mystery, adventure or history. Whether it’s an Egyptian temple whispering ancient secrets or a pirate skull guarding hidden treasure, these environments make the tank more meaningful to its owner.
- Functional Fantasy: Each 3D print doubles as a cave or hideout, enriching your pet’s environment. These are not just ornaments — they’re playgrounds and shelters. Fish find safe retreats, reptiles enjoy basking spots and small creatures get cozy corners to explore.
- Educational and Customizable: Themes like ancient Egypt or Roman architecture offer educational value for curious minds and can even inspire young aquarists. With 3D printing, every detail — from size to surface texture — can be customized to suit your specific species or tank style.
- Budget-Friendly Artistry: Compared to store-bought pieces that often lack character and cost far more, printed designs provide creative flexibility without breaking the bank. You get artisan-style decor at a DIY price.
Explore My Latest Themed 3D Print Designs
🏺 The Secrets of Pharaoh: Egyptian Themed Cave
Inspired by the pages of The Complete Gods and Goddesses of Ancient Egypt by Richard H. Wilkinson, this design brings mystery and myth to every tank. As I flipped through pages of forgotten temples, sunlit columns and silent tombs, I imagined how incredible it would be to bring that ancient atmosphere into aquariums and terrariums making themed 3D print decor. That same evening, I opened my 3D modeling software and began sketching. What emerged was the first draft of the Secrets of Pharaoh — a Egyptian themed cave structure designed not just for aesthetics, but to tell a story beneath the water or serve as terrarium hides.
- Visuals: Crafted with a warm sandstone-like filament, this 3D print captures the mystique of ancient Egypt. The central sphinx sculpture sits partially buried in pale, fine-grain substrate, while the cave itself arches overhead like a natural sandstone cutaway. Hieroglyphs are intricately etched along the back wall, adding authentic texture and historical depth. The layered sediment effect of the outer walls blends seamlessly into the environment, making it appear as if the ruins were unearthed from the desert itself.
- Ideal Use: Perfect centerpiece for smaller or nano tanks, has multiple access holes for shrimp, loaches and plecos. Also a perfect fit for terrariums.
- Printing Tips:
- Print with PETG for durability and heat resistance — especially for underwater Aquarium use and Terrarium hides with warm temperature and / or UV.
- Most models need minimal or no supports.
- Placement: Best when placed against the front glass with 2mm gravel.
☠️ The Skull Hide – Pirate Cave
The inspiration for this design came when I remembered scenes from the Pirates of the Caribbean: The Price of Freedom book — the dramatic skulls and hidden treasures sparked the idea to recreate something equally cinematic as a themed 3D print design for an aquarium or terrarium.
- Visuals: Unmistakably dramatic and boldly adventurous, the Skull Hide – Pirate Cave is type of 3D print caves, that will always draw attention. This design features a weathered, partially buried skull with a cavernous open mouth, designed to resemble a forgotten pirate hideout. Printed in matte white filament, the structure takes on an eerie, stone-like appearance when surrounded by soft sand and lush greenery. The skull’s eye sockets and mouth are carved deep, doubling as spacious hideouts or swim-throughs for aquatic pets. The cutaway views reveal the internal space beneath the skull—perfect for bottom dwellers like plecos or loaches to explore. Textured interior walls and a naturally sloped floor give the cave a realistic subterranean feel. With its layered substrate design and front-glass visibility, this piece creates an immersive visual that feels like it’s been excavated straight from a pirate’s lair.
- Pet Appeal: Great for reptiles like geckos or snakes, as well as smaller aquarium bottom dwellers.
- Printing Tips:
- Print with PETG for durability and heat resistance — especially for underwater Aquarium use and Terrarium hides with warm temperature and / or UV.
- Overhangs need supports to maintain texture detail — avoiding them can reduce visual impact.
- Placement: Designed to touch the front glass and integrate into the tank’s foreground.
🏛️ The Sunken Colosseum Cave
Brought to life by a love for Roman history and the movie Gladiator, this cave mimics the architecture of the iconic amphitheater. I’ve always loved the Roman history and architecture of the Colosseum and while watching the movie I started thinking — how could I incorporate that iconic structure into a functional themed 3D print decor? So The Sunken Colosseum is what I came up with and I think it really looks amazing!
- Visuals: Printed in white filament, the cave structure features archways and stepped textures that resemble the original Colosseum’s architecture. The structure is embedded into the tank’s corner, forming a seamless transition from natural gravel to historical ruin. Its twin observation windows — visible from both glass panels — offer an open flow for aquatic or terrestrial creatures to explore and hide within.
- Best For: Bottom dwellers like kuhli loaches and plecos. Designed for mid-range & larger tanks.
- Printing Tips:
- Neutral filament tones aged with moss or algae.
- Requires support structures to retain the beauty of its arches and internal recesses — skipping supports may affect final quality.
- Print with PETG for underwater use in Aquariums and UV / heat resistance in Terrarium setups.
- Placement: Designed as a corner cave with one big entry opening in the top and two observation windows from sides — touches both front and side glass.
How to Print and Set Up My Themed Decor
Setup Notes
- All three themed caves look and function best when surrounded by ~2 mm fraction gravel for a stable and natural setup.
- Egyptian and Pirate designs are front-placed; Colosseum is engineer to fit into tank corners.
- Keep in mind, that highly detailed prints may result in sharp edges. Always sand the 3D print caves down with any type of sandpaper before placing them in your aquarium or terrarium to keep your pets safe!
Print & Filament Guide
| Design | Time | Filament | Settings |
|---|---|---|---|
| The Secrets of Pharaoh | ~6 hr | ~80g, PETG | 0.2mm layer, 15% infill |
| Skull Hide – Pirate Cave | ~7 hr | ~90g, PETG | 0.2mm, 15–20%, supports needed |
| The Sunken Colosseum | ~8 hr | ~100g, PETG | 0.2mm, 20%, supports needed |
Wondering why I recommend PETG over PLA? Read here & here for all the details and knowledge!
- Cost per model: under $4 in filament — depending on the size you print, of course. But no matter the scale, printing these kinds of detailed designs yourself saves a lot of money compared to buying themed decor in stores.
- Retail price for similar decor: $80+ and themed decor like that would be near to impossible to find.
Final Thoughts: More Than Just Decor
Themed setups are absolutely worth trying. Not only do they enhance the aesthetic of your tank, but they also offer enrichment for your pets and a new layer of enjoyment for you as a hobbyist. There’s something magical about watching your loaches swim through a Colosseum arch or your gecko curl up under a pirate’s cave.
🔥 Now, I’d love to hear from you! Which theme should I design next? Drop your ideas in the comments— Vikings, Atlantis, Samurai or entirely something else? Let’s co-create this world together.
And if you found this guide helpful or know someone who’s into aquariums or terrariums, share this article! Let’s grow a vibrant, friendly and sharing community that inspires and supports one another through creativity, print by print.