Looking to Build a Beautiful Aquarium but Tight on Space?

Let us run through our 10 best nano/small fish. Nano tanks—generally under 60 litres—are the perfect solution. With a wide variety of small, peaceful fish available, you can create a colourful, active aquascape in even the smallest home or office. Whether you are a beginner or an experienced aquarist, this guide introduces the top 10 best nano fish that are ideal for compact tanks, offering personality, vibrant colours, and easy care in one tiny package.

1. Endler Guppy (Poecilia wingei)

Size: Up to 3 cm. Tank Size: 30L+. Temperament: Peaceful. Best Setup: Planted nano or community tank. Why we love them: Endless colour morphs, easy to breed, beginner-friendly.

2. Chili Rasbora (Boraras brigittae)

Size: 2 cm. Tank Size: 20L+. Temperament: Peaceful. Best Setup: Blackwater style with dense plants. Why we love them: Bold red colour in a tiny fish with a calm nature.

3. Pygmy Corydoras (Corydoras pygmaeus)

Size: 2.5 cm. Tank Size: 30L+. Temperament: Peaceful bottom dweller. Best Setup: Sand substrate with cover and swimming space. Why we love them: Constant movement, very social.

4. Neon Tetra (Paracheirodon innesi)

Size: 3.5 cm. Tank Size: 40L+. Temperament: Peaceful. Best Setup: Moderately planted, stable water. Why we love them: Bright flashes of blue and red—an iconic nano choice.

5. Pea Puffer (Carinotetraodon travancoricus)

Size: Up to 2.5 cm. Tank Size: 30L+ (solo). Temperament: Semi-aggressive. Best Setup: Heavily planted with enrichment. Why we love them: Small, expressive, and full of character.

6. Celestial Pearl Danio or Galaxy Rasbora (Danio margaritatus)

Size: 2 cm. Tank Size: 30L+. Temperament: Peaceful but shy. Best Setup: Well-planted with open swimming room. Why we love them: Star-like spots and fiery red fins.

7. Ember Tetra (Hyphessobrycon amandae)

Size: 2 cm. Tank Size: 30L+. Temperament: Peaceful. Best Setup: Dark substrate and plants to bring out colour. Why we love them: Glowing orange bodies and excellent schooling behaviour.

8. Sparkling Gourami (Trichopsis pumila)

Size: 3.5 cm. Tank Size: 30L+. Temperament: Peaceful (can be territorial). Best Setup: Calm water, lots of cover, low light. Why we love them: Shimmery scales and soft chirping sounds.

9. Emerald Dwarf Rasbora (Microrasbora erythromicron)

Size: 2 cm. Tank Size: 30L+. Temperament: Peaceful, slightly shy. Best Setup: Heavily planted with gentle flow and some shaded areas. Notes: Does best in groups of 6 or more. Why we love them: Gorgeous green shimmer with orange fins—tiny but striking.

10. Green Neon Tetra (Paracheirodon simulans)

Size: 3 cm. Tank Size: 30L+. Temperament: Peaceful. Best Setup: Similar to standard Neons, but prefers slightly softer water. Why we love them: More subtle but highly iridescent; perfect for lush scapes.

Tips for a Successful Nano Tank

Choose peaceful, compatible species. Stick to a school or a centrepiece fish. Avoid overstocking, as less is more. Regular water changes are essential. Live plants help balance the environment.

Nano Essentials at Byrkley Aquatics

We provide nano aquariums and starter kits, colour-boosting foods, live foods for tiny fish, low-grow plants for small tanks, and mini filters and heaters.

Conclusion

Nano aquariums are a fantastic way to enjoy the beauty of tropical fish in a smaller space, and the species we have listed are some of the best suited for compact setups. However, it is important to remember that while these fish are all small in size, they do not all thrive in the same conditions or make good tank mates. Some prefer soft, acidic water, while others need slightly harder, more alkaline environments. Certain species, like the Pea Puffer, are best kept alone, while others do well in peaceful groups of their own kind. For the healthiest tank and happiest fish, research each species' requirements carefully and consider setting up single-species or carefully selected community tanks. When done right, a nano aquarium can be a vibrant, thriving centrepiece full of personality and colour.

Ready to build your dream nano setup? Visit us in-store or browse our nano range online today!