Creating a vibrant, thriving aquarium starts with selecting the right fish. For hobbyists and professionals alike, small fish offer color, movement, and character without overwhelming the space or other inhabitants. In this comprehensive guide, we explore the best small fish for aquariums, diving deep into their care requirements, compatibility, and unique characteristics.
Whether you’re setting up a nano tank or adding to a larger community aquarium, understanding your options is crucial. With a focus on aesthetics, behaviour and ease of care, this article serves as your go-to resource for choosing the best small fish for aquariums.
Before we dive in, lets look at the tank set ups you’ll need for small fish.
Ideal Tank Setups for Small Fish
Nano aquariums typically range from 45-60 litres. They are ideal for small fish species like Chili Rasboras, Endler’s Livebearers, and Pygmy Corydoras. These tanks require stable water conditions due to limited volume, so a reliable heater, filter, and consistent maintenance are crucial. Avoid overcrowding and overfeeding, and use plants like Java Moss or Anubias to provide cover and enhance water quality.
Community aquariums house multiple species that coexist peacefully. A good size for a community tank starts at 150 litres. Fish such as Neon Tetras, Guppies, Harlequin Rasboras, and Corydoras do well in these setups. Ensure all species have compatible water parameters.
Compatibility Chart
| Fish | Compatible With |
|---|---|
| Neon Tetra | Guppies, Corydoras, Harlequin Rasboras |
| Betta (Male) | Snails, Pygmy Corydoras, Ember Tetras (caution) |
| Guppy | Endlers, Mollies, White Cloud Minnows |
| Dwarf Gourami | Tetras, Rasboras, Otocinclus |
| Celestial Pearl Danio | Shrimp, Rasboras, Pygmy Corydoras |
| Chili Rasbora | Shrimp, Snails, Pygmy Corydoras |
Feeding Tips for Small Aquarium Fish
• Diversity: Offer flakes, pellets, live, and frozen food.
• Portion Control: Feed only what can be consumed in 2 minutes.
• Targeted Feeding: Use pipettes for bottom feeders.
• Supplements: Use spirulina, garlic, and colour-enhancing foods occasionally.
Aquascaping for Small Fish
Java Moss, Anubias, Cryptocoryne, floating plants, driftwood, rock caves, and leaf litter enhance comfort and aesthetics. Read our article of aquascaping for small fish here.
Frequently Asked Questions
Q: Can I keep small fish in a bowl?
A: No. Bowls often lack filtration and space. A minimum 45 litre tank is recommended.
Q: How many small fish can I keep in a 45 litre tank?
A: Follow the 1 inch per 4 liters rule as a general guide.
Q: Do small fish need heaters?
A: Most tropical small fish do, except for cool-water species like White Cloud Mountain Minnows.
Q: How often should I clean the tank?
A: Weekly water changes (20–30%) and monthly filter maintenance.
Q: Can I breed small fish in a community tank?
A: Yes, particularly livebearers like guppies, though fry may be eaten without separation.
The Top 15 Small Fish For Your Aquarium
1. Neon Tetra (Paracheirodon innesi)
Overview: Bright blue and red stripes make this one of the most popular aquarium fish.
Size: 1.5 inches
Lifespan: 5–10 years
Tank Size: 10 gallons
Water Parameters: pH 6.0–7.0, Temp 70–81°F
Compatibility: Peaceful, best in schools of 6+.
Feeding: Flakes, micro-pellets, frozen daphnia.
2. Guppy (Poecilia reticulata)
Overview: Hardy, colorful, and easy to breed, guppies are ideal for beginners.
Size: 1.5–2.5 inches
Lifespan: 2–3 years
Tank Size: 5 gallons+
Water Parameters: pH 6.8–7.8, Temp 72–82°F
Compatibility: Peaceful; avoid fin-nippers.
Feeding: Flakes, baby brine shrimp, bloodworms.
3. Betta Fish (Betta splendens)
Overview: Known for stunning fins and solitary temperament.
Size: 2.5–3 inches
Lifespan: 3–5 years
Tank Size: 5 gallons minimum
Water Parameters: pH 6.5–7.5, Temp 76–82°F
Compatibility: Males should be housed alone.
Feeding: Pellets, bloodworms, mosquito larvae.
4. Cherry Barb (Puntius titteya)
Overview: Bright red coloration in males and peaceful schooling behavior.
Size: 2 inches
Lifespan: 4–7 years
Tank Size: 20 gallons
Water Parameters: pH 6.0–8.0, Temp 73–81°F
Compatibility: Good with other peaceful community fish.
Feeding: Flakes, micro-pellets, live food.
5. Harlequin Rasbora (Trigonostigma heteromorpha)
Overview: Hardy and peaceful, with a distinctive black triangle mark.
Size: 2 inches
Lifespan: 5–8 years
Tank Size: 10 gallons
Water Parameters: pH 6.0–7.5, Temp 72–81°F
Compatibility: Excellent in schools of 6+, ideal for community tanks.
Feeding: Flakes, micro-pellets, daphnia.
6. Corydoras Catfish (Corydoras spp.)
Overview: Bottom-dwellers that help keep the substrate clean.
Size: 1–2.5 inches depending on species
Lifespan: 5–10 years
Tank Size: 15 gallons+
Water Parameters: pH 6.0–7.8, Temp 72–78°F
Compatibility: Peaceful, best in groups of 4+.
Feeding: Sinking pellets, algae wafers, live/frozen food.
7. Celestial Pearl Danio (Danio margaritatus)
Overview: Nano fish with shimmering spots and a peaceful temperament.
Size: 0.75–1 inch
Lifespan: 3–5 years
Tank Size: 10 gallons
Water Parameters: pH 6.5–7.5, Temp 72–78°F
Compatibility: Good with shrimp and other small peaceful fish.
Feeding: Micro-pellets, crushed flakes, baby brine shrimp.
8. Endler’s Livebearer (Poecilia wingei)
Overview: Small, flashy livebearers similar to guppies but more compact.
Size: 1 inch
Lifespan: 2–3 years
Tank Size: 5 gallons minimum
Water Parameters: pH 6.5–8.0, Temp 72–82°F
Compatibility: Great for nano tanks, peaceful.
Feeding: Crushed flakes, daphnia, microworms.
9. White Cloud Mountain Minnow (Tanichthys albonubes)
Overview: Cold-water species, ideal for unheated tanks.
Size: 1.5 inches
Lifespan: 3–5 years
Tank Size: 10 gallons
Water Parameters: pH 6.0–8.0, Temp 60–72°F
Compatibility: Great in schools, peaceful.
Feeding: Flakes, small pellets, frozen foods.
10. Dwarf Gourami (Trichogaster lalius)
Overview: Peaceful centerpiece fish with vivid color.
Size: 2–3.5 inches
Lifespan: 4–6 years
Tank Size: 15 gallons minimum
Water Parameters: pH 6.0–7.5, Temp 76–82°F
Compatibility: Peaceful with caution; avoid fin-nippers.
Feeding: Pellets, bloodworms, brine shrimp.
11. Ember Tetra (Hyphessobrycon amandae)
Overview: A fiery orange gem perfect for nano tanks, Ember Tetras are active and peaceful.
Size: 0.8 inches
Lifespan: 2–4 years
Tank Size: 10 gallons
Water Parameters: pH 5.5–7.0, Temp 73–84°F
Compatibility: Great in schools of 6+. Combine with rasboras, Corydoras, and dwarf shrimp.
Feeding: Tiny flakes, micro pellets, and baby brine shrimp.
12. Pygmy Corydoras (Corydoras pygmaeus)
Overview: One of the smallest catfish, perfect for planted nano tanks.
Size: 0.75–1 inch
Lifespan: 3–5 years
Tank Size: 10 gallons
Water Parameters: pH 6.0–7.5, Temp 72–78°F
Compatibility: Needs to be in groups of 6+. Great with tetras, rasboras, and shrimp.
Feeding: Sinking micro-pellets, algae wafers, and live microfauna.
13. Sparkling Gourami (Trichopsis pumila)
Overview: Tiny, glittering gouramis with a pleasant chattering vocalization.
Size: 1.5 inches
Lifespan: 4–5 years
Tank Size: 10 gallons
Water Parameters: pH 6.0–7.5, Temp 76–82°F
Compatibility: Peaceful but shy. Avoid boisterous fish.
Feeding: Micropellets, brine shrimp, mosquito larvae.
14. Chili Rasbora (Boraras brigittae)
Overview: A nano tank favorite, the Chili Rasbora adds a bold red streak in tiny spaces.
Size: 0.7 inches
Lifespan: 4–6 years
Tank Size: 5 gallons minimum
Water Parameters: pH 4.0–7.0, Temp 68–82°F
Compatibility: Loves company – keep in groups of 8+. Best with shrimp and snails.
Feeding: Tiny live foods, powdered flakes, microworms.
15. Least Killifish (Heterandria formosa)
Overview: Among the smallest livebearers, they are ideal for beginners and low-tech tanks.
Size: 0.5–1 inch
Lifespan: 3 years
Tank Size: 5 gallons
Water Parameters: pH 6.5–8.0, Temp 68–78°F
Compatibility: Gentle and great for planted tanks. Coexist well with shrimp and snails.
Feeding: Crushed flakes, daphnia, infusoria.
Conclusion
Choosing the best small fish for aquariums involves more than just picking what looks pretty. It’s about understanding the fish’s needs, ensuring compatibility, and creating a harmonious ecosystem. From Neon Tetras to Sparkling Gouramis, each species brings unique qualities to your tank.
This guide equips aquarists to make informed choices, whether you’re a beginner with a nano setup or a seasoned hobbyist curating a diverse community tank. Remember: a balanced tank with happy, healthy fish is always the most beautiful.
