The Betta Fish in a Natural Aquarium: Give It a Peaceful Haven Without a Filter
F. MattierThis is undoubtedly the most famous fish, but also the most misunderstood in our hobby. Betta splendens, or Siamese fighting fish, is a victim of its own hardiness. Capable of surviving in extreme conditions, it is too often condemned to boredom in tiny one-liter cubes or, conversely, tossed into community tanks equipped with circulation pumps that exhaust it.
With its long, flowing fins, the Betta hates currents. It comes from rice paddies, marshes, and calm, shallow waters in Southeast Asia. That is why keeping a fighting fish in an aquarium without a filter or pump is not a whim: it is an exact recreation of its preferred biotope. As an ethology enthusiast, I am here to guide you in creating the natural aquarium for bettas it deserves.
Adapting a fascinating fish (the labyrinth organ and rest)
To understand how to arrange its space, we need to observe its biology. The Betta has a unique respiratory organ called the labyrinth organ. This fascinating adaptation allows it to breathe atmospheric air directly at the surface, a vital adaptation in the warm, stagnant waters of its native habitat, which are sometimes low in dissolved oxygen.
In everyday life, it is an observant fish and, let’s admit it, a little “lazy.” It is not built for endurance swimming. It likes to settle down, rest on a broad leaf near the surface, and observe its territory. For these breaks, I highly recommend Om Kop (Limnophila rugosa). This incredible plant, with broad, textured leaves scented with anise, readily grows above the water. It creates perfect plant hammocks for your pet’s long naps.
👉 Give it natural hammocks with our Limnophila rugosa (Om Kop).
Arranging the surface and providing mental stimulation
The surface is the Betta’s domain. This is where it breathes, hunts, and builds its famous bubble nests for reproduction.
Floating plants are essential for making it feel secure. Floating frogbit (Limnobium) will provide long, trailing roots, ideal for structuring the upper area of the tank and anchoring its bubble nests. Other floating plants, such as Salvinia minima or Phyllantus, will nicely complete the surface, although they do not have these long roots. Warning: however, make sure never to let small floating plants, such as duckweed or Azollas, cover 100% of the surface, because your Betta must always be able to access the open air to breathe.
👉 Secure the surface with our indoor floating plants.
Beyond the surface, the betta splendens in a low-tech aquarium needs a complex environment. By creating a genuine maze of roots and dense plants, you provide complexity that makes exploration exciting and never-ending for the fish. This is fundamental for keeping it occupied and stimulating its intelligence. The volume “perceived” by the fish is infinitely greater when it lives in a lush jungle rather than in a desperately empty tank.
Natural feeding: the pleasure of micro-meals
Forget dry flakes and industrial pellets. The Betta is a micro-predator and surface hunter. Live food for fighting fish is not a luxury; it is a vital physiological and psychological need that stimulates its hunting instinct.
Offer it our full range of live prey suited to the size of its mouth: Daphnia that will swim in open water, Grindal worm, Enchytraeids, Tubifex, or Blackworm that will awaken its curiosity at the bottom, and even Springtails that will hop across the surface.
The immense advantage of live food lies in its feeding behavior. The Betta does not eat everything at once. Live food remains available in the tank without polluting the water. This allows it to have dozens of micro-meals throughout its wanderings in the plant maze, precisely recreating its wild lifestyle.
👉 Awaken its hunting instinct with our live food cultures.
Technology reduced to the bare minimum
The advantage of a biologically designed tank is that it does without noisy and unattractive technology. At the temperatures found in modern homes today, which rarely fall below 20°C, a heater may not even be necessary for a very densely planted and covered tank.
The only technology truly required is good lighting. This light is not there to illuminate the fish, but to grow the colossal plant mass which, together with the soil microbiome, continuously purifies the water—something no filter will ever do.
Conclusion
Let us restore dignity to the Siamese fighting fish. Let us take it out of tiny jars and artificial currents and offer it the richness of a recreated natural biotope. Celebrating the beauty of a Betta splendens means watching it thrive, peaceful and lively, in a calm-water jungle where every leaf is a new trail to explore.
Mattier
FAQ: Creating the ideal aquarium for a Siamese fighting fish
What is the ideal aquarium size for a Betta without a filter?
When asked which aquarium is suitable for a fighting fish, the answer is clear: forget the 2- or 5-liter “betta splendens kits.” A net volume of 20 to 30 liters is the absolute minimum for a single Betta. This volume allows you to install enough plant mass to ensure natural purification (low-tech) and provide the space needed for this curious fish to explore.
Can a fighting fish live with snails and microfauna?
Yes, it is even highly recommended! Snails (Ramshorn snails, Bladder snails) and microfauna (Ostracods, Water lice) are your invisible maintenance crew. They clean the bottom and the biofilm. Your Betta may hunt a few young ostracods or baby snails, but this is part of natural regulation and contributes to its behavioral enrichment. Feel free to start the tank with a ZollaBox Starter to introduce this valuable life.
How should you feed your Betta while on vacation?
The advantage of a natural aquarium without a filter is its autonomy. If you leave for a week, your Betta will not starve. It will spend its time hunting the endemic microfauna—aquatic worms, daphnia, and ostracods—living in the plant maze. If you leave for longer, ask someone close to you to provide a portion of live food, such as Grindal worm or daphnia, which will live in the tank until eaten without risking water pollution, unlike dry pellets given in excess.